#!/usr/bin/env dub
/+ dub.sdl:
    name "platform_ui_portal_appearance"
    targetPath "build"
    platforms "linux"
    dflags "-preview=in" "-preview=dip1000"
    buildType "checked" {
        buildOptions "optimize" "inline" "debugInfo"
    }
+/
/**
 * Reading the desktop's appearance preferences through the XDG portal.
 *
 * `org.freedesktop.portal.Settings` is the one route that works on **both**
 * GNOME and KDE (and on any other desktop shipping a portal backend), from
 * inside a sandbox or out, without linking a toolkit. The
 * `org.freedesktop.appearance` namespace is the vendor-neutral part:
 *
 * | Key              | Type    | Values                                       |
 * | ---------------- | ------- | -------------------------------------------- |
 * | `color-scheme`   | `u`     | 0 no preference · 1 prefer-dark · 2 prefer-light |
 * | `accent-color`   | `(ddd)` | sRGB in [0,1]; out-of-range ⇒ unset          |
 * | `contrast`       | `u`     | 0 normal · 1 higher contrast                 |
 * | `reduced-motion` | `u`     | 0 no preference · 1 reduced                  |
 *
 * The program reads each key, reports which ones the *running* backend actually
 * implements, and derives the scheme. Two findings this example exists to make
 * visible, both observed rather than assumed:
 *
 *   - **The namespace is not uniformly implemented.** A key defined in the
 *     current spec can be absent from a deployed backend, answered as
 *     `org.freedesktop.portal.Error.NotFound`. Which keys are missing differs
 *     between GNOME and KDE — see [../index.md](../index.md) § "Coverage is
 *     per-backend" and [../../kde.md](../../kde.md).
 *   - **`accent-color` promises more than GNOME delivers.** The type is an
 *     arbitrary sRGB triple, but `xdg-desktop-portal-gnome` converts a
 *     nine-value `AdwAccentColor` enum to RGB at the boundary, so the answer is
 *     always one of nine hexes. See [../../libadwaita.md](../../libadwaita.md).
 *
 * Companion to docs/research/platform-ui-guidelines/gnome/index.md
 *   § "The portal route" and § "Change notification".
 *
 * Run with: dub run --single portal-appearance.d
 *
 * Portability: Linux only. It shells out to `gdbus` (or `busctl`) rather than
 * marshalling D-Bus itself — the deep-dive's § "What a D implementation needs"
 * records that a real client wants a D-Bus binding, which Sparkles does not have
 * yet. With no session bus, no portal, or neither helper on `PATH` it prints a
 * `SKIP:` line and exits 0, which is how CI runs it.
 */
module 
(module) platform_ui_portal_appearance
Reading the desktop's appearance preferences through the XDG portal.
org.freedesktop.portal.Settings is the one route that works on both
GNOME and KDE (and on any other desktop shipping a portal backend), from
inside a sandbox or out, without linking a toolkit. The
org.freedesktop.appearance namespace is the vendor-neutral part:
Key 
Type 
Values 
color-scheme 
u 
0 no preference · 1 prefer-dark · 2 prefer-light 
accent-color 
(ddd) 
sRGB in 0,1; out-of-range ⇒ unset 
contrast 
u 
0 normal · 1 higher contrast 
reduced-motion 
u 
0 no preference · 1 reduced 
The program reads each key, reports which ones the running backend actually
implements, and derives the scheme. Two findings this example exists to make
visible, both observed rather than assumed:
The namespace is not uniformly implemented. A key defined in the
    current spec can be absent from a deployed backend, answered as
    org.freedesktop.portal.Error.NotFound. Which keys are missing differs
    between GNOME and KDE — see ../index.md § "Coverage is
    per-backend" and ../../kde.md.
accent-color promises more than GNOME delivers. The type is an
    arbitrary sRGB triple, but xdg-desktop-portal-gnome converts a
    nine-value AdwAccentColor enum to RGB at the boundary, so the answer is
    always one of nine hexes. See ../../libadwaita.md.
Companion to docs/research/platform-ui-guidelines/gnome/index.md
§ "The portal route" and § "Change notification".
Run with: dub run --single portal-appearance.d
Portability
Linux only. It shells out to gdbus (or busctl) rather than
marshalling D-Bus itself — the deep-dive's § "What a D implementation needs"
records that a real client wants a D-Bus binding, which Sparkles does not have
yet. With no session bus, no portal, or neither helper on PATH it prints a
SKIP: line and exits 0, which is how CI runs it.platform_ui_portal_appearance;

import 
(package) stdstd.
(module) std.algorithm
This package implements generic algorithms oriented towards the processing of
sequences. Sequences processed by these functions define range-based
interfaces.  See also Reference on ranges and
tutorial on ranges.
Algorithms are categorized into the following submodules:
Submodule 
Functions 
|      Searching |
all
any
balancedParens
boyerMooreFinder
canFind
commonPrefix
count
countUntil
endsWith
find
findAdjacent
findAmong
findSkip
findSplit
findSplitAfter
findSplitBefore
minCount
maxCount
minElement
maxElement
minIndex
maxIndex
minPos
maxPos
skipOver
startsWith
until
|
|     Comparison |
among
castSwitch
clamp
cmp
either
equal
isPermutation
isSameLength
levenshteinDistance
levenshteinDistanceAndPath
max
min
mismatch
predSwitch
|
|     Iteration |
cache
cacheBidirectional
chunkBy
cumulativeFold
each
filter
filterBidirectional
fold
group
joiner
map
mean
permutations
reduce
splitWhen
splitter
substitute
sum
uniq
|
|     Sorting |
completeSort
isPartitioned
isSorted
isStrictlyMonotonic
ordered
strictlyOrdered
makeIndex
merge
multiSort
nextEvenPermutation
nextPermutation
nthPermutation
partialSort
partition
partition3
schwartzSort
sort
topN
topNCopy
topNIndex
|
|     Set operations (setops) |
cartesianProduct
largestPartialIntersection
largestPartialIntersectionWeighted
multiwayMerge
multiwayUnion
setDifference
setIntersection
setSymmetricDifference
|
|     Mutation |
bringToFront
copy
fill
initializeAll
move
moveAll
moveSome
moveEmplace
moveEmplaceAll
moveEmplaceSome
remove
reverse
strip
stripLeft
stripRight
swap
swapRanges
uninitializedFill
|
Many functions in this package are parameterized with a predicate.
The predicate may be any suitable callable type
(a function, a delegate, a functor, or a lambda), or a
compile-time string. The string may consist of any legal D
expression that uses the symbol a (for unary functions) or the
symbols a and b (for binary functions). These names will NOT
interfere with other homonym symbols in user code because they are
evaluated in a different context. The default for all binary
comparison predicates is "a == b" for unordered operations and
"a < b" for ordered operations.
Example
int[] a = ...;
static bool greater(int a, int b)
{
    return a > b;
}
sort!greater(a);           // predicate as alias
sort!((a, b) => a > b)(a); // predicate as a lambda.
sort!"a > b"(a);           // predicate as string
                           // (no ambiguity with array name)
sort(a);                   // no predicate, "a < b" is implicit
Source
std/algorithm/package.d
@copyrightAndrei Alexandrescu 2008-.@licenseBoost License 1.0.@authorsAndrei Alexandrescualgorithm : 
(alias template) platform_ui_portal_appearance.canFind = std.algorithm.searching.canFind(alias pred = "a == b")
Convenience function. Like find, but only returns whether or not the search
was successful.
For more information about pred see find.
@seeamong for checking a value against multiple arguments.canFind, 
(alias template) platform_ui_portal_appearance.findSplit = std.algorithm.searching.findSplit(alias pred = "a == b", R1, R2)(R1 haystack, R2 needle) if (isForwardRange!R1 && isForwardRange!R2)
These functions find the first occurrence of needle in haystack and then
split haystack as follows.
findSplit returns a tuple result containing three ranges.
result[0] is the portion of haystack before needle
result[1] is the portion of
    haystack that matches needle
result[2] is the portion of haystack
    after the match.
If needle was not found, result[0] comprehends haystack
entirely and result[1] and result[2] are empty.
findSplitBefore returns a tuple result containing two ranges.
result[0] is the portion of haystack before needle
result[1] is the balance of haystack starting with the match.
If needle was not found, result[0]
comprehends haystack entirely and result[1] is empty.
findSplitAfter returns a tuple result containing two ranges.
result[0] is the portion of haystack up to and including the
    match
result[1] is the balance of haystack starting
    after the match.
If needle was not found, result[0] is empty
and result[1] is haystack.
In all cases, the concatenation of the returned ranges spans the
entire haystack.
If haystack is a random-access range, all three components of the tuple have
the same type as haystack. Otherwise, haystack must be a
forward range and
the type of result[0] (and result[1] for findSplit) is the same as
the result of takeExactly.
For more information about pred see find.
@parampred Predicate to compare 2 elements.@paramhaystack The forward range to search.@paramneedle The forward range to look for.@returnsA sub-type of Tuple of the split portions of haystack (see above for
details). This sub-type of Tuple defines opCast!bool, which
returns true when the separating needle was found and false otherwise.@seefindfindSplit, 
(alias template) platform_ui_portal_appearance.startsWith = std.algorithm.searching.startsWith(alias pred = (a, b) => a == b, Range, Needles...)(Range doesThisStart, Needles withOneOfThese) if (isInputRange!Range && (Needles.length > 1) && allSatisfy!(canTestStartsWith!(pred, Range), Needles))
Checks whether the given
input range starts with (one
of) the given needle(s) or, if no needles are given,
if its front element fulfils predicate pred.
For more information about pred see find.
@parampred Predicate to use in comparing the elements of the haystack and the needle(s). Mandatory if no needles are given.@paramdoesThisStart The input range to check.@paramwithOneOfThese The needles against which the range is to be checked, which may be individual elements or input ranges of elements.@paramwithThis The single needle to check, which may be either a single element or an input range of elements.@returns
0 if the needle(s) do not occur at the beginning of the given range;
otherwise the position of the matching needle, that is, 1 if the range starts
with withOneOfThese[0], 2 if it starts with withOneOfThese[1], and so
on.
In the case where doesThisStart starts with multiple of the ranges or
elements in withOneOfThese, then the shortest one matches (if there are
two which match which are of the same length (e.g. "a" and 'a'), then
the left-most of them in the argument
list matches).
In the case when no needle parameters are given, return true iff front of
doesThisStart fulfils predicate pred.startsWith;
import 
(package) stdstd.
(module) std.conv
A one-stop shop for converting values from one type to another.
Category 
Functions 
Generic 
asOriginalType castFrom parse to toChars bitCast 
Strings 
text wtext dtext writeText writeWText writeDText hexString 
Numeric 
octal roundTo signed unsigned 
Exceptions 
ConvException ConvOverflowException 
Source
std/conv.d
@copyrightCopyright The D Language Foundation 2007-.@licenseBoost License 1.0.@authorsWalter Bright,
Andrei Alexandrescu,
Shin Fujishiro,
Adam D. Ruppe,
Kenji Haraconv : 
(alias template) platform_ui_portal_appearance.to = std.conv.to(T)
The to template converts a value from one type to another.
The source type is deduced and the target type must be specified, for example the
expression to`!int(42.0)` converts the number 42 from
`double` to `int`. The conversion is "safe", i.e.,
it checks for overflow; to!int(4.2e10) would throw the
ConvOverflowException exception. Overflow checks are only
inserted when necessary, e.g., ``to!double(42) does not do
any checking because any int fits in a double.
Conversions from string to numeric types differ from the C equivalents
atoi() and atol() by checking for overflow and not allowing whitespace.
For conversion of strings to signed types, the grammar recognized is:
Integer:
Sign UnsignedInteger
UnsignedInteger
Sign:
+
-
For conversion to unsigned types, the grammar recognized is:
UnsignedInteger:
DecimalDigit
DecimalDigit UnsignedIntegerto;
import 
(package) stdstd.
(module) std.format
This package provides string formatting functionality using
printf style format strings.
Submodule 
Function Name 
Description 
package 
format 
Converts its arguments according to a format string into a string. 
|     package |
sformat |
Converts its arguments according to a format string into a buffer. |
|     package |
FormatException |
Signals a problem while formatting. |
|     write |
formattedWrite |
Converts its arguments according to a format string and writes
the result to an output range. |
|     write |
formatValue |
Formats a value of any type according to a format specifier and
writes the result to an output range. |
|     read |
formattedRead |
Reads an input range according to a format string and stores the read
values into its arguments. |
|     read |
unformatValue |
Reads a value from the given input range and converts it according to
a format specifier. |
|     spec |
FormatSpec |
A general handler for format strings. |
|     spec |
singleSpec |
Helper function that returns a FormatSpec for a single format specifier. |
Limitation
This package does not support localization, but
adheres to the rounding mode of the floating point unit, if
available.
Format Strings
The functions contained in this package use format strings. A
format string describes the layout of another string for reading or
writing purposes. A format string is composed of normal text
interspersed with format specifiers. A format specifier starts
with a percentage sign '%', optionally followed by one or more
parameters and ends with a format indicator. A format
indicator may be a simple format character or a compound
indicator.
Format strings are composed according to the following grammar:
FormatString:
FormatStringItem FormatString
FormatStringItem:
Character
FormatSpecifier
FormatSpecifier:
'%' Parameters FormatIndicator
FormatIndicator:
FormatCharacter
CompoundIndicator
FormatCharacter:
see remark below
CompoundIndicator:
'(' FormatString '%)'
'(' FormatString '%|' Delimiter '%)'
Delimiter
empty
Character Delimiter
Parameters:
Position Flags Width Precision Separator
Position:
empty
Integer '$'**
*Integer* **':'** *Integer* **'$'
Integer ':' '$'**
*Flags*:
*empty*
*Flag* *Flags*
*Flag*:
**'-'**|**'+'**|**'&nbsp;'**|**'0'**|**'#'**|**'='**
*Width*:
*OptionalPositionalInteger*
*Precision*:
*empty*
**'.'** *OptionalPositionalInteger*
*Separator*:
*empty*
**','** *OptionalInteger*
**','** *OptionalInteger* **'?'**
*OptionalInteger*:
*empty*
*Integer*
**'*'**
*OptionalPositionalInteger*:
*OptionalInteger*
**'*'** *Integer* **'$'
Character
'%%'
AnyCharacterExceptPercent
Integer:
NonZeroDigit Digits
Digits:
empty
Digit Digits
NonZeroDigit:
'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9'
Digit:
'0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9'
Note
FormatCharacter is unspecified. It can be any character
that has no other purpose in this grammar, but it is
recommended to assign (lower- and uppercase) letters.
Note
The Parameters of a CompoundIndicator are currently
limited to a '-' flag.
Format Indicator
The format indicator can either be a single character or an
expression surrounded by '%(' and '%)'. It specifies the
basic manner in which a value will be formatted and is the minimum
requirement to format a value.
The following characters can be used as format characters:
FormatCharacter 
Semantics 
's' 
To be formatted in a human readable format.
Can be used with all types. 
'c' 
To be formatted as a character. 
'd' 
To be formatted as a signed decimal integer. 
'u' 
To be formatted as a decimal image of the underlying bit representation. 
'b' 
To be formatted as a binary image of the underlying bit representation. 
'o' 
To be formatted as an octal image of the underlying bit representation. 
'x' / 'X' 
To be formatted as a hexadecimal image of the underlying bit representation. 
'e' / 'E' 
To be formatted as a real number in decimal scientific notation. 
'f' / 'F' 
To be formatted as a real number in decimal natural notation. 
'g' / 'G' 
To be formatted as a real number in decimal short notation.
Depending on the number, a scientific notation or
a natural notation is used. 
'a' / 'A' 
To be formatted as a real number in hexadecimal scientific notation. 
'r' 
To be formatted as raw bytes.
The output may not be printable and depends on endianness. 
The compound indicator can be used to describe compound types
like arrays or structs in more detail. A compound type is enclosed
within '%(' and '%)'. The enclosed sub-format string is
applied to individual elements. The trailing portion of the
sub-format string following the specifier for the element is
interpreted as the delimiter, and is therefore omitted following the
last element. The '%|' specifier may be used to explicitly
indicate the start of the delimiter, so that the preceding portion of
the string will be included following the last element.
The format string inside of the compound indicator should
contain exactly one format specifier (two in case of associative
arrays), which specifies the formatting mode of the elements of the
compound type. This format specifier can be a compound
indicator itself.
Note
Inside a compound indicator, strings and characters are
escaped automatically. To avoid this behavior, use "%-("
instead of "%(".
Flags
There are several flags that affect the outcome of the formatting.
Flag 
Semantics 
'-' 
When the formatted result is shorter than the value
given by the width parameter, the output is left
justified. Without the '-' flag, the output remains
right justified.
There are two exceptions where the '-' flag has a
different meaning: (1) with 'r' it denotes to use little
endian and (2) in case of a compound indicator it means that
no special handling of the members is applied. |
| '=' |
When the formatted result is shorter than the value
given by the width parameter, the output is centered.
If the central position is not possible it is moved slightly
to the right. In this case, if '-' flag is present in
addition to the '=' flag, it is moved slightly to the left. |
| '+'&nbsp;/&nbsp;*'&nbsp;'* |
Applies to numerical values. By default, positive numbers are not
formatted to include the + sign. With one of these two flags present,
positive numbers are preceded by a plus sign or a space.
When both flags are present, a plus sign is used.
In case of 'r', a big endian format is used. |
| '0' |
Is applied to numerical values that are printed right justified.
If the zero flag is present, the space left to the number is
filled with zeros instead of spaces. |
| '#' |
Denotes that an alternative output must be used. This depends on the type
to be formatted and the format character used. See the
sections below for more information. |
Width, Precision and Separator
The width parameter specifies the minimum width of the result.
The meaning of precision depends on the format indicator. For
integers it denotes the minimum number of digits printed, for
real numbers it denotes the number of fractional digits and for
strings and compound types it denotes the maximum number of elements
that are included in the output.
A separator is used for formatting numbers. If it is specified,
the output is divided into chunks of three digits, separated by a ','. The number of digits in a chunk can be given explicitly by
providing a number or a ''* after the ','.
In all three cases the number of digits can be replaced by a ''*. In this scenario, the next argument is used as the number of
digits. If the argument is a negative number, the precision and
separator parameters are considered unspecified. For width,
the absolute value is used and the '-' flag is set.
The separator can also be followed by a '?'. In that case,
an additional argument is used to specify the symbol that should be
used to separate the chunks.
Position
By default, the arguments are processed in the provided order. With
the position parameter it is possible to address arguments
directly. It is also possible to denote a series of arguments with
two numbers separated by ':', that are all processed in the same
way. The second number can be omitted. In that case the series ends
with the last argument.
It's also possible to use positional arguments for width, precision and separator by adding a number and a '$' after the ''*.
Types
This section describes the result of combining types with format
characters. It is organized in 2 subsections: a list of general
information regarding the formatting of types in the presence of
format characters and a table that contains details for every
available combination of type and format character.
When formatting types, the following rules apply:
If the format character is upper case, the resulting string will
    be formatted using upper case letters.
The default precision for floating point numbers is 6 digits.
Rounding of floating point numbers adheres to the rounding mode
    of the floating point unit, if available.
The floating point values NaN and Infinity are formatted as
    nan and inf, possibly preceded by '+' or '-' sign.
Formatting reals is only supported for 64 bit reals and 80 bit reals.
    All other reals are cast to double before they are formatted. This will
    cause the result to be inf for very large numbers.
Characters and strings formatted with the 's' format character
    inside of compound types are surrounded by single and double quotes
    and unprintable characters are escaped. To avoid this, a '-'
    flag can be specified for the compound specifier
    (e.g. "%-(%s%)" instead of "%(%s%)" ).
Structs, unions, classes and interfaces are formatted by calling a
    toString method if available.
    See module std.format.write for more
    details.
Only part of these combinations can be used for reading. See
    module std.format.read for more
    detailed information.
This table contains descriptions for every possible combination of
type and format character:
<th scope="col" width="20%">Type</th> <th scope="col" width="20%">Format Character</th>  Formatted as... 
<td rowspan="1">null</td> 's' 
null 
|<td rowspan="3">bool</td> 's' |
false or true |
| 'b', 'd', 'o', 'u', 'x', 'X' |
As the integrals 0 or 1 with the same format character.
Please note, that 'o' and 'x' with '#' flag
might produce unexpected results due to special handling of
the value 0. |
| 'r' |
\0 or \1 |
|<td rowspan="4">Integral</td> 's', 'd' |
A signed decimal number. The '#' flag is ignored. |
| 'b', 'o', 'u', 'x', 'X' |
An unsigned binary, decimal, octal or hexadecimal number.
In case of 'o' and 'x', the '#' flag
denotes that the number must be preceded by 0 and 0x, with
the exception of the value 0, where this does not apply. For
'b' and 'u' the '#' flag has no effect. |
| 'e', 'E', 'f', 'F', 'g', 'G', 'a', 'A' |
As a floating point value with the same specifier.
Default precision is large enough to add all digits
of the integral value.
In case of 'a' and 'A', the integral digit can be
any hexadecimal digit.
|
| 'r' |
Characters taken directly from the binary representation. |
|<td rowspan="5">Floating Point</td> 'e', 'E' |
Scientific notation: Exactly one integral digit followed by a dot
and fractional digits, followed by the exponent.
The exponent is formatted as 'e' followed by
a '+' or '-' sign, followed by at least
two digits.
When there are no fractional digits and the '#' flag
is not present, the dot is omitted. |
| 'f', 'F' |
Natural notation: Integral digits followed by a dot and
fractional digits.
When there are no fractional digits and the '#' flag
is not present, the dot is omitted.
Please note: the difference between 'f' and 'F'
is only visible for NaN and Infinity. |
| 's', 'g', 'G' |
Short notation: If the absolute value is larger than 10 ^^ precision
or smaller than 0.0001, the scientific notation is used.
If not, the natural notation is applied.
In both cases precision denotes the count of all digits, including
the integral digits. Trailing zeros (including a trailing dot) are removed.
If '#' flag is present, trailing zeros are not removed. |
| 'a', 'A' |
Hexadecimal scientific notation: 0x followed by 1
(or 0 in case of value zero or denormalized number)
followed by a dot, fractional digits in hexadecimal
notation and an exponent. The exponent is build by p,
followed by a sign and the exponent in decimal notation.
When there are no fractional digits and the '#' flag
is not present, the dot is omitted. |
| 'r' |
Characters taken directly from the binary representation. |
|<td rowspan="3">Character</td> 's', 'c' |
As the character.
Inside of a compound indicator 's' is treated differently: The
character is surrounded by single quotes and non printable
characters are escaped. This can be avoided by preceding
the compound indicator with a '-' flag
(e.g. "%-(%s%)"). |
| 'b', 'd', 'o', 'u', 'x', 'X' |
As the integral that represents the character. |
| 'r' |
Characters taken directly from the binary representation. |
|<td rowspan="3">String</td> 's' |
The sequence of characters that form the string.
Inside of a compound indicator the string is surrounded by double quotes
and non printable characters are escaped. This can be avoided
by preceding the compound indicator with a '-' flag
(e.g. "%-(%s%)"). |
| 'r' |
The sequence of characters, each formatted with 'r'. |
| compound |
As an array of characters. |
|<td rowspan="3">Array</td> 's' |
When the elements are characters, the array is formatted as
a string. In all other cases the array is surrounded by square brackets
and the elements are separated by a comma and a space. If the elements
are strings, they are surrounded by double quotes and non
printable characters are escaped. |
| 'r' |
The sequence of the elements, each formatted with 'r'. |
| compound |
The sequence of the elements, each formatted according to the specifications
given inside of the compound specifier. |
|<td rowspan="2">Associative Array</td> 's' |
As a sequence of the elements in unpredictable order. The output is
surrounded by square brackets. The elements are separated by a
comma and a space. The elements are formatted as key:value. |
| compound |
As a sequence of the elements in unpredictable order. Each element
is formatted according to the specifications given inside of the
compound specifier. The first specifier is used for formatting
the key and the second specifier is used for formatting the value.
The order can be changed with positional arguments. For example
"%(%2$s (%1$s), %)" will write the value, followed by the key in
parenthesis. |
|<td rowspan="2">Enum</td> 's' |
The name of the value. If the name is not available, the base value
is used, preceeded by a cast. |
| All, but 's' |
Enums can be formatted with all format characters that can be used
with the base value. In that case they are formatted like the base value. |
|<td rowspan="3">Input Range</td> 's' |
When the elements of the range are characters, they are written like a string.
In all other cases, the elements are enclosed by square brackets and separated
by a comma and a space. |
| 'r' |
The sequence of the elements, each formatted with 'r'. |
| compound |
The sequence of the elements, each formatted according to the specifications
given inside of the compound specifier. |
|<td rowspan="1">Struct</td> 's' |
When the struct has neither an applicable toString
nor is an input range, it is formatted as follows:
StructType(field1, field2, ...). |
|<td rowspan="1">Class</td> 's' |
When the class has neither an applicable toString
nor is an input range, it is formatted as the
fully qualified name of the class. |
|<td rowspan="1">Union</td> 's' |
When the union has neither an applicable toString
nor is an input range, it is formatted as its base name. |
|<td rowspan="2">Pointer</td> 's' |
A null pointer is formatted as 'null'. All other pointers are
formatted as hexadecimal numbers with the format character 'X'. |
| 'x', 'X' |
Formatted as a hexadecimal number. |
|<td rowspan="3">SIMD vector</td> 's' |
The array is surrounded by square brackets
and the elements are separated by a comma and a space. |
| 'r' |
The sequence of the elements, each formatted with 'r'. |
| compound |
The sequence of the elements, each formatted according to the specifications
given inside of the compound specifier. |
|<td rowspan="1">Delegate</td> 's', 'r', compound |
As the .stringof of this delegate treated as a string.
Please note: The implementation is currently buggy
and its use is discouraged. |
Source
std/format/package.d
Examples
Simple use:
// Easiest way is to use `%s` everywhere:
assert(format("I got %s %s for %s euros.", 30, "eggs", 5.27) == "I got 30 eggs for 5.27 euros.");

// Other format characters provide more control:
assert(format("I got %b %(%X%) for %f euros.", 30, "eggs", 5.27) == "I got 11110 65676773 for 5.270000 euros.");
Compound specifiers allow formatting arrays and other compound types:
/*
The trailing end of the sub-format string following the specifier for
each item is interpreted as the array delimiter, and is therefore
omitted following the last array item:
 */
    assert(format("My items are %(%s %).", [1,2,3]) == "My items are 1 2 3.");
    assert(format("My items are %(%s, %).", [1,2,3]) == "My items are 1, 2, 3.");

/*
The "%|" delimiter specifier may be used to indicate where the
delimiter begins, so that the portion of the format string prior to
it will be retained in the last array element:
 */
    assert(format("My items are %(-%s-%|, %).", [1,2,3]) == "My items are -1-, -2-, -3-.");

/*
These compound format specifiers may be nested in the case of a
nested array argument:
 */
    auto mat = [[1, 2, 3],
                [4, 5, 6],
                [7, 8, 9]];

    assert(format("%(%(%d %) - %)", mat), "1 2 3 - 4 5 6 - 7 8 9");
    assert(format("[%(%(%d %) - %)]", mat), "[1 2 3 - 4 5 6 - 7 8 9]");
    assert(format("[%([%(%d %)]%| - %)]", mat), "[1 2 3] - [4 5 6] - [7 8 9]");

/*
Strings and characters are escaped automatically inside compound
format specifiers. To avoid this behavior, use "%-(" instead of "%(":
 */
    assert(format("My friends are %s.", ["John", "Nancy"]) == `My friends are ["John", "Nancy"].`);
    assert(format("My friends are %(%s, %).", ["John", "Nancy"]) == `My friends are "John", "Nancy".`);
    assert(format("My friends are %-(%s, %).", ["John", "Nancy"]) == `My friends are John, Nancy.`);
Using parameters:
// Flags can be used to influence to outcome:
assert(format("%g != %+#g", 3.14, 3.14) == "3.14 != +3.14000");

// Width and precision help to arrange the formatted result:
assert(format(">%10.2f<", 1234.56789) == ">   1234.57<");

// Numbers can be grouped:
assert(format("%,4d", int.max) == "21,4748,3647");

// It's possible to specify the position of an argument:
assert(format("%3$s %1$s", 3, 17, 5) == "5 3");
Providing parameters as arguments:
// Width as argument
assert(format(">%*s<", 10, "abc") == ">       abc<");

// Precision as argument
assert(format(">%.*f<", 5, 123.2) == ">123.20000<");

// Grouping as argument
assert(format("%,*d", 1, int.max) == "2,1,4,7,4,8,3,6,4,7");

// Grouping separator as argument
assert(format("%,3?d", '_', int.max) == "2_147_483_647");

// All at once
assert(format("%*.*,*?d", 20, 15, 6, '/', int.max) == "   000/002147/483647");
@copyrightCopyright The D Language Foundation 2000-2021.@licenseBoost License 1.0.@authorsWalter Bright, Andrei Alexandrescu, and Kenji Haraformat : 
(alias template) platform_ui_portal_appearance.format = std.format.format(Char, Args...)(in Char[] fmt, Args args) if (isSomeChar!Char)
Converts its arguments according to a format string into a string.
The second version of format takes the format string as template
argument. In this case, it is checked for consistency at
compile-time and produces slightly faster code, because the length of
the output buffer can be estimated in advance.
@paramfmt a format string@paramargs a variadic list of arguments to be formatted@paramChar character type of fmt@paramArgs a variadic list of types of the arguments@returnsThe formatted string.@throwsA FormatException if formatting did not succeed.@seesformat for a variant, that tries to avoid garbage collection.format;
import 
(package) stdstd.
(module) std.process
Functions for starting and interacting with other processes, and for
working with the current process' execution environment.
Process handling
`spawnProcess` spawns a new `process`, optionally assigning it an
    
arbitrary set of standard input, output, and error streams.
    The function returns immediately, leaving the child process to execute
    in parallel with its parent.  All other functions in this module that
    spawn processes are built around spawnProcess.
`wait` makes the parent `process` wait for a child `process` to
    
terminate.  In general one should always do this, to avoid
    child processes becoming "zombies" when the parent process exits.
    Scope guards are perfect for this – see the spawnProcess
    documentation for examples.  tryWait is similar to wait,
    but does not block if the process has not yet terminated.
`pipeProcess` also spawns a child `process` which runs
    
in parallel with its parent.  However, instead of taking
    arbitrary streams, it automatically creates a set of
    pipes that allow the parent to communicate with the child
    through the child's standard input, output, and/or error streams.
    This function corresponds roughly to C's popen function.
`execute` starts a new `process` and waits for it
    
to complete before returning.  Additionally, it captures
    the process' standard output and error streams and returns
    the output of these as a string.
`spawnShell`, `pipeShell` and `executeShell` work like
    
spawnProcess, pipeProcess and execute, respectively,
    except that they take a single command string and run it through
    the current user's default command interpreter.
    executeShell corresponds roughly to C's system function.
`kill` attempts to terminate a running `process`.

The following table compactly summarises the different process creation
functions and how they relate to each other:
Runs program directly 
Runs shell command 
Low-level process creation 
spawnProcess 
spawnShell 
Automatic input/output redirection using pipes 
pipeProcess 
pipeShell 
Execute and wait for completion, collect output 
execute 
executeShell 
Other functionality
`pipe` is used to create unidirectional pipes.
`environment` is an interface through which the current `process`'
    
environment variables can be read and manipulated.
`escapeShellCommand` and `escapeShellFileName` are useful
    
for constructing shell command lines in a portable way.
Source
std/process.d
Note
Most of the functionality in this module is not available on iOS, tvOS
and watchOS. The only functions available on those platforms are:
environment, thisProcessID and thisThreadID.
@authorsLars Tandle Kyllingstad,
Steven Schveighoffer,
Vladimir Panteleev@copyrightCopyright (c) 2013, the authors. All rights reserved.@licenseBoost License 1.0.process : 
(class) std.process.environment
Manipulates environment variables using an associative-array-like
interface.
This class contains only static methods, and cannot be instantiated.
See below for examples of use.environment, 
(alias) platform_ui_portal_appearance.execute = std.typecons.Tuple!(int, "status", string, "output") std.process.execute(scope const(char[])[] args, const(string[string]) env = cast(const(string[string]))null, std.process.Config config = Config(Flags.none, null, null), ulong maxOutput = 18446744073709551615LU, scope const(char)[] workDir = null) @safe
Executes the given program or shell command and returns its exit
code and output.
execute and executeShell start a new process using
spawnProcess and spawnShell, respectively, and wait
for the process to complete before returning.  The functions capture
what the child process prints to both its standard output and
standard error streams, and return this together with its exit code.
auto dmd = execute(["dmd", "myapp.d"]);
if (dmd.status != 0) writeln("Compilation failed:\n", dmd.output);

auto ls = executeShell("ls -l");
if (ls.status != 0) writeln("Failed to retrieve file listing");
else writeln(ls.output);
The args/program/command, env and config
parameters are forwarded straight to the underlying spawn functions,
and we refer to their documentation for details.
POSIX specific
If the process is terminated by a signal, the status field of
the return value will contain a negative number whose absolute
value is the signal number.  (See wait for details.)
@paramargs An array which contains the program name as the zeroth element and any command-line arguments in the following elements. (See spawnProcess for details.)@paramprogram The program name, without command-line arguments. (See spawnProcess for details.)@paramcommand A shell command which is passed verbatim to the command interpreter. (See spawnShell for details.)@paramenv Additional environment variables for the child process. (See spawnProcess for details.)@paramconfig Flags that control process creation. See Config for an overview of available flags, and note that the retainStd... flags have no effect in this function.@parammaxOutput The maximum number of bytes of output that should be captured.@paramworkDir The working directory for the new process. By default the child process inherits the parent's working directory.@paramshellPath The path to the shell to use to run the specified program. By default this is nativeShell.@returnsAn std.typecons.Tuple!(int, "status", string, "output").@throws
ProcessException on failure to start the process.
StdioException on failure to capture output.execute;
import 
(package) stdstd.
(module) std.stdio
Category 
Symbols 
File handles 
_popen File isFileHandle openNetwork stderr stdin stdout 
Reading 
chunks lines readf readfln readln 
Writing 
toFile write writef writefln writeln 
Misc 
KeepTerminator LockType StdioException 
Standard I/O functions that extend core.stdc.stdio.  core.stdc.stdio
is publically imported when importing std.stdio.
There are three layers of I/O:
The lowest layer is the operating system layer. The two main schemes are Windows and Posix.
C's stdio.h which unifies the two operating system schemes.
std.stdio, this module, unifies the various stdio.h implementations into
    a high level package for D programs.
Source
std/stdio.d
@copyrightCopyright The D Language Foundation 2007-.@licenseBoost License 1.0.@authorsWalter Bright,
Andrei Alexandrescu,
Alex Rønne Petersenstdio : 
(alias template) platform_ui_portal_appearance.writefln = std.stdio.writefln(alias fmt, A...)(A args) if (isSomeString!(typeof(fmt)))
Equivalent to writef(fmt, args, '\n').writefln, 
(alias template) platform_ui_portal_appearance.writeln = std.stdio.writeln(T...)(T args)
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln;
import 
(package) stdstd.
(module) std.string
String handling functions.
Category 
Functions 
Searching 
column
indexOf
indexOfAny
indexOfNeither
lastIndexOf
lastIndexOfAny
lastIndexOfNeither
Comparison 
isNumeric
Mutation 
capitalize
Pruning and Filling 
center
chomp
chompPrefix
chop
detabber
detab
entab
entabber
leftJustify
outdent
rightJustify
strip
stripLeft
stripRight
wrap
Substitution 
abbrev
soundex
soundexer
succ
tr
translate
Miscellaneous 
assumeUTF
fromStringz
lineSplitter
representation
splitLines
toStringz
Objects of types string, wstring, and dstring are value types
and cannot be mutated element-by-element. For using mutation during building
strings, use char[], wchar[], or dchar[]. The xxxstring
types are preferable because they don't exhibit undesired aliasing, thus
making code more robust.
The following functions are publicly imported:
Module 
Functions 
Publicly imported functions
std.algorithm 
cmp, std,algorithm,comparison
count, std,algorithm,searching
endsWith, std,algorithm,searching
startsWith, std,algorithm,searching
std.array 
join, std,array
replace, std,array
replaceInPlace, std,array
split, std,array
empty, std,array
std.format 
format, std,format
sformat, std,format
std.uni 
icmp, std,uni
toLower, std,uni
toLowerInPlace, std,uni
toUpper, std,uni
toUpperInPlace, std,uni
There is a rich set of functions for string handling defined in other modules.
Functions related to Unicode and ASCII are found in std.uni
and std.ascii, respectively. Other functions that have a
wider generality than just strings can be found in std.algorithm
and std.range.
Source
std/string.d
@seestd.algorithm and
std.range
for generic range algorithms
,
std.ascii
for functions that work with ASCII strings
,
std.uni
for functions that work with unicode strings@copyrightCopyright The D Language Foundation 2007-.@licenseBoost License 1.0.@authorsWalter Bright,
Andrei Alexandrescu,
Jonathan M Davis,
and David L. 'SpottedTiger' Davisstring : 
(alias template) platform_ui_portal_appearance.strip = std.string.strip(Range)(Range str) if (isSomeString!Range || isRandomAccessRange!Range && hasLength!Range && hasSlicing!Range && !isConvertibleToString!Range && isSomeChar!(ElementEncodingType!Range))
Strips both leading and trailing whitespace (as defined by
isWhite) or as specified in the second argument.
@paramstr string or random access range of characters@paramchars string of characters to be stripped@paramleftChars string of leading characters to be stripped@paramrightChars string of trailing characters to be stripped@returnsslice of str stripped of leading and trailing whitespace
or characters as specified in the second argument.@seeGeneric stripping on ranges: stripstrip;

enum 
(constant) string platform_ui_portal_appearance.portalDest = "org.freedesktop.portal.Desktop"portalDest = "org.freedesktop.portal.Desktop";
enum 
(constant) string platform_ui_portal_appearance.portalPath = "/org/freedesktop/portal/desktop"portalPath = "/org/freedesktop/portal/desktop";
enum 
(constant) string platform_ui_portal_appearance.appearance = "org.freedesktop.appearance"appearance = "org.freedesktop.appearance";

/// The outcome of one `ReadOne` call: the raw reply, or the reason there is none.
struct 
(struct) platform_ui_portal_appearance.KeyResult
The outcome of one ReadOne call: the raw reply, or the reason there is none.KeyResult
{
    bool 
(field) bool platform_ui_portal_appearance.KeyResult.ok
a value came backok;         /// a value came back
    bool 
(field) bool platform_ui_portal_appearance.KeyResult.notFound
the backend does not implement this keynotFound;   /// the backend does not implement this key
    
(alias) object.string = stringstring 
(field) string platform_ui_portal_appearance.KeyResult.raw
verbatim reply (or error text)raw;      /// verbatim reply (or error text)
}

/// Locate a D-Bus command-line client. `gdbus` ships with GLib, `busctl` with
/// systemd; a desktop running a portal has at least one.
(alias) object.string = stringstring 
string platform_ui_portal_appearance.findDbusTool() @safe
Locate a D-Bus command-line client. gdbus ships with GLib, busctl with
systemd; a desktop running a portal has at least one.findDbusTool() @safe
{
    foreach (
(parameter) string tooltool; ["gdbus", "busctl"])
    {
        const 
(local variable) const(std.typecons.Tuple!(int, "status", string, "output")) rr = 
std.typecons.Tuple!(int, "status", string, "output") std.process.execute(scope const(char[])[] args, const(string[string]) env = cast(const(string[string]))null, std.process.Config config = Config(Flags.none, null, null), ulong maxOutput = 18446744073709551615LU, scope const(char)[] workDir = null) @safe
Executes the given program or shell command and returns its exit
code and output.
execute and executeShell start a new process using
spawnProcess and spawnShell, respectively, and wait
for the process to complete before returning.  The functions capture
what the child process prints to both its standard output and
standard error streams, and return this together with its exit code.
auto dmd = execute(["dmd", "myapp.d"]);
if (dmd.status != 0) writeln("Compilation failed:\n", dmd.output);

auto ls = executeShell("ls -l");
if (ls.status != 0) writeln("Failed to retrieve file listing");
else writeln(ls.output);
The args/program/command, env and config
parameters are forwarded straight to the underlying spawn functions,
and we refer to their documentation for details.
POSIX specific
If the process is terminated by a signal, the status field of
the return value will contain a negative number whose absolute
value is the signal number.  (See wait for details.)
@paramargs An array which contains the program name as the zeroth element and any command-line arguments in the following elements. (See spawnProcess for details.)@paramprogram The program name, without command-line arguments. (See spawnProcess for details.)@paramcommand A shell command which is passed verbatim to the command interpreter. (See spawnShell for details.)@paramenv Additional environment variables for the child process. (See spawnProcess for details.)@paramconfig Flags that control process creation. See Config for an overview of available flags, and note that the retainStd... flags have no effect in this function.@parammaxOutput The maximum number of bytes of output that should be captured.@paramworkDir The working directory for the new process. By default the child process inherits the parent's working directory.@paramshellPath The path to the shell to use to run the specified program. By default this is nativeShell.@returnsAn std.typecons.Tuple!(int, "status", string, "output").@throws
ProcessException on failure to start the process.
StdioException on failure to capture output.execute(["sh", "-c", "command -v " ~ 
(local variable) string tooltool]);
        if (
(local variable) const(std.typecons.Tuple!(int, "status", string, "output")) rr.status == 0 && 
(field) int std.typecons.Tuple!(int, "status", string, "output").__expand_field_0r.output.
string std.string.strip!string(string str) pure nothrow @nogc @safe
Strips both leading and trailing whitespace (as defined by
isWhite) or as specified in the second argument.
Examples
import std.uni : lineSep, paraSep;
assert(strip("     hello world     ") ==
       "hello world");
assert(strip("\n\t\v\rhello world\n\t\v\r") ==
       "hello world");
assert(strip("hello world") ==
       "hello world");
assert(strip([lineSep] ~ "hello world" ~ [lineSep]) ==
       "hello world");
assert(strip([paraSep] ~ "hello world" ~ [paraSep]) ==
       "hello world");
@paramstr string or random access range of characters@paramchars string of characters to be stripped@paramleftChars string of leading characters to be stripped@paramrightChars string of trailing characters to be stripped@returnsslice of str stripped of leading and trailing whitespace
or characters as specified in the second argument.@seeGeneric stripping on ranges: stripstrip.
(field) string std.typecons.Tuple!(int, "status", string, "output").__expand_field_1length)
            return 
(local variable) string tooltool;
    }
    return null;
}

/// `org.freedesktop.portal.Settings.ReadOne(namespace, key)`.
///
/// `ReadOne` — not `Read`. The spec marks `Read` deprecated because it
/// "returns the value wrapped in two variant layers instead of one"; `ReadOne`
/// was added in interface version 2.
(struct) platform_ui_portal_appearance.KeyResult
The outcome of one ReadOne call: the raw reply, or the reason there is none.KeyResult 
platform_ui_portal_appearance.KeyResult platform_ui_portal_appearance.readOne(string tool, string key) @safe
org.freedesktop.portal.Settings.ReadOne(namespace, key).
ReadOne — not Read. The spec marks Read deprecated because it
"returns the value wrapped in two variant layers instead of one"; ReadOne
was added in interface version 2.readOne(
(alias) object.string = stringstring 
(parameter) string tooltool, 
(alias) object.string = stringstring 
(parameter) string keykey) @safe
{
    
(alias) object.string = stringstring[] 
(local variable) string[] argvargv = 
(parameter) string tooltool == "gdbus"
        ? [
            "gdbus", "call", "--session", "--dest", 
(constant) string platform_ui_portal_appearance.portalDest = "org.freedesktop.portal.Desktop"portalDest,
            "--object-path", 
(constant) string platform_ui_portal_appearance.portalPath = "/org/freedesktop/portal/desktop"portalPath,
            "--method", "org.freedesktop.portal.Settings.ReadOne",
            
(constant) string platform_ui_portal_appearance.appearance = "org.freedesktop.appearance"appearance, 
(parameter) string keykey,
        ]
        : [
            "busctl", "--user", "call", 
(constant) string platform_ui_portal_appearance.portalDest = "org.freedesktop.portal.Desktop"portalDest, 
(constant) string platform_ui_portal_appearance.portalPath = "/org/freedesktop/portal/desktop"portalPath,
            "org.freedesktop.portal.Settings", "ReadOne", "ss", 
(constant) string platform_ui_portal_appearance.appearance = "org.freedesktop.appearance"appearance, 
(parameter) string keykey,
        ];

    const 
(local variable) const(std.typecons.Tuple!(int, "status", string, "output")) rr = 
std.typecons.Tuple!(int, "status", string, "output") std.process.execute(scope const(char[])[] args, const(string[string]) env = cast(const(string[string]))null, std.process.Config config = Config(Flags.none, null, null), ulong maxOutput = 18446744073709551615LU, scope const(char)[] workDir = null) @safe
Executes the given program or shell command and returns its exit
code and output.
execute and executeShell start a new process using
spawnProcess and spawnShell, respectively, and wait
for the process to complete before returning.  The functions capture
what the child process prints to both its standard output and
standard error streams, and return this together with its exit code.
auto dmd = execute(["dmd", "myapp.d"]);
if (dmd.status != 0) writeln("Compilation failed:\n", dmd.output);

auto ls = executeShell("ls -l");
if (ls.status != 0) writeln("Failed to retrieve file listing");
else writeln(ls.output);
The args/program/command, env and config
parameters are forwarded straight to the underlying spawn functions,
and we refer to their documentation for details.
POSIX specific
If the process is terminated by a signal, the status field of
the return value will contain a negative number whose absolute
value is the signal number.  (See wait for details.)
@paramargs An array which contains the program name as the zeroth element and any command-line arguments in the following elements. (See spawnProcess for details.)@paramprogram The program name, without command-line arguments. (See spawnProcess for details.)@paramcommand A shell command which is passed verbatim to the command interpreter. (See spawnShell for details.)@paramenv Additional environment variables for the child process. (See spawnProcess for details.)@paramconfig Flags that control process creation. See Config for an overview of available flags, and note that the retainStd... flags have no effect in this function.@parammaxOutput The maximum number of bytes of output that should be captured.@paramworkDir The working directory for the new process. By default the child process inherits the parent's working directory.@paramshellPath The path to the shell to use to run the specified program. By default this is nativeShell.@returnsAn std.typecons.Tuple!(int, "status", string, "output").@throws
ProcessException on failure to start the process.
StdioException on failure to capture output.execute(
(local variable) string[] argvargv);
    const 
(local variable) const(string) texttext = 
(local variable) const(std.typecons.Tuple!(int, "status", string, "output")) rr.output.
string std.string.strip!string(string str) pure nothrow @nogc @safe
Strips both leading and trailing whitespace (as defined by
isWhite) or as specified in the second argument.
Examples
import std.uni : lineSep, paraSep;
assert(strip("     hello world     ") ==
       "hello world");
assert(strip("\n\t\v\rhello world\n\t\v\r") ==
       "hello world");
assert(strip("hello world") ==
       "hello world");
assert(strip([lineSep] ~ "hello world" ~ [lineSep]) ==
       "hello world");
assert(strip([paraSep] ~ "hello world" ~ [paraSep]) ==
       "hello world");
@paramstr string or random access range of characters@paramchars string of characters to be stripped@paramleftChars string of leading characters to be stripped@paramrightChars string of trailing characters to be stripped@returnsslice of str stripped of leading and trailing whitespace
or characters as specified in the second argument.@seeGeneric stripping on ranges: stripstrip;
    if (
(local variable) const(std.typecons.Tuple!(int, "status", string, "output")) rr.status == 0)
        return 
(struct) platform_ui_portal_appearance.KeyResult
The outcome of one ReadOne call: the raw reply, or the reason there is none.KeyResult(ok: true, raw: 
(local variable) const(string) texttext);
    return 
(struct) platform_ui_portal_appearance.KeyResult
The outcome of one ReadOne call: the raw reply, or the reason there is none.KeyResult(
        notFound: 
(local variable) const(string) texttext.
bool std.algorithm.searching.canFind!().canFind!(string, string)(string haystack, scope string needle) pure nothrow @nogc @safe
Convenience function. Like find, but only returns whether or not the search
was successful.
For more information about pred see find.
Examples
const arr = [0, 1, 2, 3];
assert(canFind(arr, 2));
assert(!canFind(arr, 4));

// find one of several needles
assert(arr.canFind(3, 2));
assert(arr.canFind(3, 2) == 2); // second needle found
assert(arr.canFind([1, 3], 2) == 2);

assert(canFind(arr, [1, 2], [2, 3]));
assert(canFind(arr, [1, 2], [2, 3]) == 1);
assert(canFind(arr, [1, 7], [2, 3]));
assert(canFind(arr, [1, 7], [2, 3]) == 2);
assert(!canFind(arr, [1, 3], [2, 4]));
assert(canFind(arr, [1, 3], [2, 4]) == 0);
Example using a custom predicate.
Note that the needle appears as the second argument of the predicate.
auto words = [
    "apple",
    "beeswax",
    "cardboard"
];
assert(!canFind(words, "bees"));
assert( canFind!((string elem, string needle) => elem.startsWith(needle))(words, "bees"));
Search for multiple items in an array of items (search for needles in an array of haystacks)
string s1 = "aaa111aaa";
string s2 = "aaa222aaa";
string s3 = "aaa333aaa";
string s4 = "aaa444aaa";
const hay = [s1, s2, s3, s4];
assert(hay.canFind!(e => e.canFind("111", "222")));
@see
among for checking a value against multiple arguments.
Returns true if and only if needle can be found in     range. Performs O(haystack.length) evaluations of pred.canFind("NotFound") || 
(local variable) const(string) texttext.
bool std.algorithm.searching.canFind!().canFind!(string, string)(string haystack, scope string needle) pure nothrow @nogc @safe
Convenience function. Like find, but only returns whether or not the search
was successful.
For more information about pred see find.
Examples
const arr = [0, 1, 2, 3];
assert(canFind(arr, 2));
assert(!canFind(arr, 4));

// find one of several needles
assert(arr.canFind(3, 2));
assert(arr.canFind(3, 2) == 2); // second needle found
assert(arr.canFind([1, 3], 2) == 2);

assert(canFind(arr, [1, 2], [2, 3]));
assert(canFind(arr, [1, 2], [2, 3]) == 1);
assert(canFind(arr, [1, 7], [2, 3]));
assert(canFind(arr, [1, 7], [2, 3]) == 2);
assert(!canFind(arr, [1, 3], [2, 4]));
assert(canFind(arr, [1, 3], [2, 4]) == 0);
Example using a custom predicate.
Note that the needle appears as the second argument of the predicate.
auto words = [
    "apple",
    "beeswax",
    "cardboard"
];
assert(!canFind(words, "bees"));
assert( canFind!((string elem, string needle) => elem.startsWith(needle))(words, "bees"));
Search for multiple items in an array of items (search for needles in an array of haystacks)
string s1 = "aaa111aaa";
string s2 = "aaa222aaa";
string s3 = "aaa333aaa";
string s4 = "aaa444aaa";
const hay = [s1, s2, s3, s4];
assert(hay.canFind!(e => e.canFind("111", "222")));
@see
among for checking a value against multiple arguments.
Returns true if and only if needle can be found in     range. Performs O(haystack.length) evaluations of pred.canFind("not found"),
        raw: 
(local variable) const(string) texttext);
}

/// Pull the first unsigned integer out of a `gdbus`/`busctl` reply.
bool 
bool platform_ui_portal_appearance.parseUint(string raw, out uint value) @safe
Pull the first unsigned integer out of a gdbus/busctl reply.parseUint(
(alias) object.string = stringstring 
(parameter) string rawraw, out uint 
(parameter) uint valuevalue) @safe
{
    // gdbus: `(<uint32 1>,)`   busctl: `v u 1`
    
(alias) object.size_t = ulongsize_t 
(local variable) ulong ii;
    while (
(local variable) ulong ii < 
(parameter) string rawraw.
(field) ulong string.lengthlength && (
(parameter) string rawraw[
(local variable) ulong ii] < '0' || 
(parameter) string rawraw[
(local variable) ulong ii] > '9'))
    {
        // Skip the "uint32"/"32" type token so its digits are not mistaken for
        // the value.
        if (
(parameter) string rawraw[
(local variable) ulong ii .. $].
bool std.algorithm.searching.startsWith!("a == b", string, string)(string doesThisStart, string withThis) pure nothrow @nogc @safe
Checks whether the given
input range starts with (one
of) the given needle(s) or, if no needles are given,
if its front element fulfils predicate pred.
For more information about pred see find.
@parampred Predicate to use in comparing the elements of the haystack and the needle(s). Mandatory if no needles are given.@paramdoesThisStart The input range to check.@paramwithOneOfThese The needles against which the range is to be checked, which may be individual elements or input ranges of elements.@paramwithThis The single needle to check, which may be either a single element or an input range of elements.@returns
0 if the needle(s) do not occur at the beginning of the given range;
otherwise the position of the matching needle, that is, 1 if the range starts
with withOneOfThese[0], 2 if it starts with withOneOfThese[1], and so
on.
In the case where doesThisStart starts with multiple of the ranges or
elements in withOneOfThese, then the shortest one matches (if there are
two which match which are of the same length (e.g. "a" and 'a'), then
the left-most of them in the argument
list matches).
In the case when no needle parameters are given, return true iff front of
doesThisStart fulfils predicate pred.startsWith("uint32"))
            
(local variable) ulong ii += "uint32".
(constant) ulong "uint32".length = 6LUlength;
        else
            
(local variable) ulong ii++;
    }
    
(alias) object.size_t = ulongsize_t 
(local variable) ulong startstart = 
(local variable) ulong ii;
    while (
(local variable) ulong ii < 
(parameter) string rawraw.
(field) ulong string.lengthlength && 
(parameter) string rawraw[
(local variable) ulong ii] >= '0' && 
(parameter) string rawraw[
(local variable) ulong ii] <= '9')
        
(local variable) ulong ii++;
    if (
(local variable) ulong ii == 
(local variable) ulong startstart)
        return false;
    
(parameter) uint valuevalue = 
(parameter) string rawraw[
(local variable) ulong startstart .. 
(local variable) ulong ii].
uint std.conv.to!uint.to!string(string __param_0) pure @safe
The to template converts a value from one type to another.
The source type is deduced and the target type must be specified, for example the
expression to`!int(42.0)` converts the number 42 from
`double` to `int`. The conversion is "safe", i.e.,
it checks for overflow; to!int(4.2e10) would throw the
ConvOverflowException exception. Overflow checks are only
inserted when necessary, e.g., ``to!double(42) does not do
any checking because any int fits in a double.
Conversions from string to numeric types differ from the C equivalents
atoi() and atol() by checking for overflow and not allowing whitespace.
For conversion of strings to signed types, the grammar recognized is:
Integer:
Sign UnsignedInteger
UnsignedInteger
Sign:
+
-
For conversion to unsigned types, the grammar recognized is:
UnsignedInteger:
DecimalDigit
DecimalDigit UnsignedInteger
Examples
Converting a value to its own type (useful mostly for generic code)
simply returns its argument.
int a = 42;
int b = to!int(a);
double c = to!double(3.14); // c is double with value 3.14
Converting among numeric types is a safe way to cast them around.
Conversions from floating-point types to integral types allow loss of
precision (the fractional part of a floating-point number). The
conversion is truncating towards zero, the same way a cast would
truncate. (To round a floating point value when casting to an
integral, use roundTo.)
import std.exception : assertThrown;

int a = 420;
assert(to!long(a) == a);
assertThrown!ConvOverflowException(to!byte(a));

assert(to!int(4.2e6) == 4200000);
assertThrown!ConvOverflowException(to!uint(-3.14));
assert(to!uint(3.14) == 3);
assert(to!uint(3.99) == 3);
assert(to!int(-3.99) == -3);
When converting strings to numeric types, note that D hexadecimal and binary
literals are not handled. Neither the prefixes that indicate the base, nor the
horizontal bar used to separate groups of digits are recognized. This also
applies to the suffixes that indicate the type.
To work around this, you can specify a radix for conversions involving numbers.
auto str = to!string(42, 16);
assert(str == "2A");
auto i = to!int(str, 16);
assert(i == 42);
Conversions from integral types to floating-point types always
succeed, but might lose accuracy. The largest integers with a
predecessor representable in floating-point format are 2^24-1 for
float, 2^53-1 for double, and 2^64-1 for real (when
real is 80-bit, e.g. on Intel machines).
// 2^24 - 1, largest proper integer representable as float
int a = 16_777_215;
assert(to!int(to!float(a)) == a);
assert(to!int(to!float(-a)) == -a);
Conversion from string types to char types enforces the input
to consist of a single code point, and said code point must
fit in the target type. Otherwise, ConvException is thrown.
import std.exception : assertThrown;

assert(to!char("a") == 'a');
assertThrown(to!char("ñ")); // 'ñ' does not fit into a char
assert(to!wchar("ñ") == 'ñ');
assertThrown(to!wchar("😃")); // '😃' does not fit into a wchar
assert(to!dchar("😃") == '😃');

// Using wstring or dstring as source type does not affect the result
assert(to!char("a"w) == 'a');
assert(to!char("a"d) == 'a');

// Two code points cannot be converted to a single one
assertThrown(to!char("ab"));
Converting an array to another array type works by converting each
element in turn. Associative arrays can be converted to associative
arrays as long as keys and values can in turn be converted.
import std.string : split;

int[] a = [1, 2, 3];
auto b = to!(float[])(a);
assert(b == [1.0f, 2, 3]);
string str = "1 2 3 4 5 6";
auto numbers = to!(double[])(split(str));
assert(numbers == [1.0, 2, 3, 4, 5, 6]);
int[string] c;
c["a"] = 1;
c["b"] = 2;
auto d = to!(double[wstring])(c);
assert(d["a"w] == 1 && d["b"w] == 2);
Conversions operate transitively, meaning that they work on arrays and
associative arrays of any complexity.
This conversion works because to`!short` applies to an `int`, to!wstring
applies to a string, to`!string` applies to a `double`, and
to!(double[]) applies to an int[]. The conversion might throw an
exception because ``to!short might fail the range check.
int[string][double[int[]]] a;
auto b = to!(short[wstring][string[double[]]])(a);
Object-to-object conversions by dynamic casting throw exception when
the source is non-null and the target is null.
import std.exception : assertThrown;
// Testing object conversions
class A {}
class B : A {}
class C : A {}
A a1 = new A, a2 = new B, a3 = new C;
assert(to!B(a2) is a2);
assert(to!C(a3) is a3);
assertThrown!ConvException(to!B(a3));
Stringize conversion from all types is supported.
String to string conversion works for any two string types having
    (char, wchar, dchar) character widths and any
    combination of qualifiers (mutable, const, or immutable).
Converts array (other than strings) to string.
    Each element is converted by calling ``to!T.
Associative array to string conversion.
    Each element is converted by calling ``to!T.
Object to string conversion calls toString against the object or
    returns "null" if the object is null.
Struct to string conversion calls toString against the struct if
    it is defined.
For structs that do not define toString, the conversion to string
    produces the list of fields.
Enumerated types are converted to strings as their symbolic names.
Boolean values are converted to "true" or "false".
char, wchar, dchar to a string type.
Unsigned or signed integers to strings.
  special case
  : Convert integral value to string in radix radix.
    radix must be a value from 2 to 36.
    value is treated as a signed value only if radix is 10.
    The characters A through Z are used to represent values 10 through 36
    and their case is determined by the letterCase parameter.
All floating point types to all string types.
Pointer to string conversions convert the pointer to a size_t value.
    If pointer is char*, treat it as C-style strings.
    In that case, this function is @system.
See formatValue on how toString should be defined.
// Conversion representing dynamic/static array with string
long[] a = [ 1, 3, 5 ];
assert(to!string(a) == "[1, 3, 5]");

// Conversion representing associative array with string
int[string] associativeArray = ["0":1, "1":2];
assert(to!string(associativeArray) == `["0":1, "1":2]` ||
       to!string(associativeArray) == `["1":2, "0":1]`);

// char* to string conversion
assert(to!string(cast(char*) null) == "");
assert(to!string("foo\0".ptr) == "foo");

// Conversion reinterpreting void array to string
auto w = "abcx"w;
const(void)[] b = w;
assert(b.length == 8);

auto c = to!(wchar[])(b);
assert(c == "abcx");
Strings can be converted to enum types. The enum member with the same name as the
input string is returned. The comparison is case-sensitive.
A ConvException is thrown if the enum does not have the specified member.
import std.exception : assertThrown;

enum E { a, b, c }
assert(to!E("a") == E.a);
assert(to!E("b") == E.b);
assertThrown!ConvException(to!E("A"));
to!uint;
    return true;
}

/// Pull the three doubles of an `(ddd)` accent reply.
bool 
bool platform_ui_portal_appearance.parseAccent(string raw, out double[3] rgb) @safe
Pull the three doubles of an (ddd) accent reply.parseAccent(
(alias) object.string = stringstring 
(parameter) string rawraw, out double[3] 
(parameter) double[3] rgbrgb) @safe
{
    
(alias) object.size_t = ulongsize_t 
(local variable) ulong cici, 
(local variable) ulong ii;
    while (
(local variable) ulong cici < 3 && 
(local variable) ulong ii < 
(parameter) string rawraw.
(field) ulong string.lengthlength)
    {
        // A double here always contains a '.', which distinguishes it from the
        // structural digits in `uint32` and from array indices.
        if ((
(parameter) string rawraw[
(local variable) ulong ii] >= '0' && 
(parameter) string rawraw[
(local variable) ulong ii] <= '9') || 
(parameter) string rawraw[
(local variable) ulong ii] == '-')
        {
            
(alias) object.size_t = ulongsize_t 
(local variable) ulong startstart = 
(local variable) ulong ii;
            while (
(local variable) ulong ii < 
(parameter) string rawraw.
(field) ulong string.lengthlength && (
                    (
(parameter) string rawraw[
(local variable) ulong ii] >= '0' && 
(parameter) string rawraw[
(local variable) ulong ii] <= '9') || 
(parameter) string rawraw[
(local variable) ulong ii] == '.'
                    || 
(parameter) string rawraw[
(local variable) ulong ii] == '-' || 
(parameter) string rawraw[
(local variable) ulong ii] == 'e' || 
(parameter) string rawraw[
(local variable) ulong ii] == '+'))
                
(local variable) ulong ii++;
            const 
(local variable) const(string) toktok = 
(parameter) string rawraw[
(local variable) ulong startstart .. 
(local variable) ulong ii];
            if (
(local variable) const(string) toktok.
bool std.algorithm.searching.canFind!().canFind!(string, char)(string haystack, scope char needle) pure @safe
Convenience function. Like find, but only returns whether or not the search
was successful.
For more information about pred see find.
Examples
const arr = [0, 1, 2, 3];
assert(canFind(arr, 2));
assert(!canFind(arr, 4));

// find one of several needles
assert(arr.canFind(3, 2));
assert(arr.canFind(3, 2) == 2); // second needle found
assert(arr.canFind([1, 3], 2) == 2);

assert(canFind(arr, [1, 2], [2, 3]));
assert(canFind(arr, [1, 2], [2, 3]) == 1);
assert(canFind(arr, [1, 7], [2, 3]));
assert(canFind(arr, [1, 7], [2, 3]) == 2);
assert(!canFind(arr, [1, 3], [2, 4]));
assert(canFind(arr, [1, 3], [2, 4]) == 0);
Example using a custom predicate.
Note that the needle appears as the second argument of the predicate.
auto words = [
    "apple",
    "beeswax",
    "cardboard"
];
assert(!canFind(words, "bees"));
assert( canFind!((string elem, string needle) => elem.startsWith(needle))(words, "bees"));
Search for multiple items in an array of items (search for needles in an array of haystacks)
string s1 = "aaa111aaa";
string s2 = "aaa222aaa";
string s3 = "aaa333aaa";
string s4 = "aaa444aaa";
const hay = [s1, s2, s3, s4];
assert(hay.canFind!(e => e.canFind("111", "222")));
@see
among for checking a value against multiple arguments.
Returns true if and only if needle can be found in     range. Performs O(haystack.length) evaluations of pred.canFind('.'))
            {
                
(parameter) double[3] rgbrgb[
(local variable) ulong cici++] = 
(local variable) const(string) toktok.
double std.conv.to!double.to!string(string __param_0) pure @safe
The to template converts a value from one type to another.
The source type is deduced and the target type must be specified, for example the
expression to`!int(42.0)` converts the number 42 from
`double` to `int`. The conversion is "safe", i.e.,
it checks for overflow; to!int(4.2e10) would throw the
ConvOverflowException exception. Overflow checks are only
inserted when necessary, e.g., ``to!double(42) does not do
any checking because any int fits in a double.
Conversions from string to numeric types differ from the C equivalents
atoi() and atol() by checking for overflow and not allowing whitespace.
For conversion of strings to signed types, the grammar recognized is:
Integer:
Sign UnsignedInteger
UnsignedInteger
Sign:
+
-
For conversion to unsigned types, the grammar recognized is:
UnsignedInteger:
DecimalDigit
DecimalDigit UnsignedInteger
Examples
Converting a value to its own type (useful mostly for generic code)
simply returns its argument.
int a = 42;
int b = to!int(a);
double c = to!double(3.14); // c is double with value 3.14
Converting among numeric types is a safe way to cast them around.
Conversions from floating-point types to integral types allow loss of
precision (the fractional part of a floating-point number). The
conversion is truncating towards zero, the same way a cast would
truncate. (To round a floating point value when casting to an
integral, use roundTo.)
import std.exception : assertThrown;

int a = 420;
assert(to!long(a) == a);
assertThrown!ConvOverflowException(to!byte(a));

assert(to!int(4.2e6) == 4200000);
assertThrown!ConvOverflowException(to!uint(-3.14));
assert(to!uint(3.14) == 3);
assert(to!uint(3.99) == 3);
assert(to!int(-3.99) == -3);
When converting strings to numeric types, note that D hexadecimal and binary
literals are not handled. Neither the prefixes that indicate the base, nor the
horizontal bar used to separate groups of digits are recognized. This also
applies to the suffixes that indicate the type.
To work around this, you can specify a radix for conversions involving numbers.
auto str = to!string(42, 16);
assert(str == "2A");
auto i = to!int(str, 16);
assert(i == 42);
Conversions from integral types to floating-point types always
succeed, but might lose accuracy. The largest integers with a
predecessor representable in floating-point format are 2^24-1 for
float, 2^53-1 for double, and 2^64-1 for real (when
real is 80-bit, e.g. on Intel machines).
// 2^24 - 1, largest proper integer representable as float
int a = 16_777_215;
assert(to!int(to!float(a)) == a);
assert(to!int(to!float(-a)) == -a);
Conversion from string types to char types enforces the input
to consist of a single code point, and said code point must
fit in the target type. Otherwise, ConvException is thrown.
import std.exception : assertThrown;

assert(to!char("a") == 'a');
assertThrown(to!char("ñ")); // 'ñ' does not fit into a char
assert(to!wchar("ñ") == 'ñ');
assertThrown(to!wchar("😃")); // '😃' does not fit into a wchar
assert(to!dchar("😃") == '😃');

// Using wstring or dstring as source type does not affect the result
assert(to!char("a"w) == 'a');
assert(to!char("a"d) == 'a');

// Two code points cannot be converted to a single one
assertThrown(to!char("ab"));
Converting an array to another array type works by converting each
element in turn. Associative arrays can be converted to associative
arrays as long as keys and values can in turn be converted.
import std.string : split;

int[] a = [1, 2, 3];
auto b = to!(float[])(a);
assert(b == [1.0f, 2, 3]);
string str = "1 2 3 4 5 6";
auto numbers = to!(double[])(split(str));
assert(numbers == [1.0, 2, 3, 4, 5, 6]);
int[string] c;
c["a"] = 1;
c["b"] = 2;
auto d = to!(double[wstring])(c);
assert(d["a"w] == 1 && d["b"w] == 2);
Conversions operate transitively, meaning that they work on arrays and
associative arrays of any complexity.
This conversion works because to`!short` applies to an `int`, to!wstring
applies to a string, to`!string` applies to a `double`, and
to!(double[]) applies to an int[]. The conversion might throw an
exception because ``to!short might fail the range check.
int[string][double[int[]]] a;
auto b = to!(short[wstring][string[double[]]])(a);
Object-to-object conversions by dynamic casting throw exception when
the source is non-null and the target is null.
import std.exception : assertThrown;
// Testing object conversions
class A {}
class B : A {}
class C : A {}
A a1 = new A, a2 = new B, a3 = new C;
assert(to!B(a2) is a2);
assert(to!C(a3) is a3);
assertThrown!ConvException(to!B(a3));
Stringize conversion from all types is supported.
String to string conversion works for any two string types having
    (char, wchar, dchar) character widths and any
    combination of qualifiers (mutable, const, or immutable).
Converts array (other than strings) to string.
    Each element is converted by calling ``to!T.
Associative array to string conversion.
    Each element is converted by calling ``to!T.
Object to string conversion calls toString against the object or
    returns "null" if the object is null.
Struct to string conversion calls toString against the struct if
    it is defined.
For structs that do not define toString, the conversion to string
    produces the list of fields.
Enumerated types are converted to strings as their symbolic names.
Boolean values are converted to "true" or "false".
char, wchar, dchar to a string type.
Unsigned or signed integers to strings.
  special case
  : Convert integral value to string in radix radix.
    radix must be a value from 2 to 36.
    value is treated as a signed value only if radix is 10.
    The characters A through Z are used to represent values 10 through 36
    and their case is determined by the letterCase parameter.
All floating point types to all string types.
Pointer to string conversions convert the pointer to a size_t value.
    If pointer is char*, treat it as C-style strings.
    In that case, this function is @system.
See formatValue on how toString should be defined.
// Conversion representing dynamic/static array with string
long[] a = [ 1, 3, 5 ];
assert(to!string(a) == "[1, 3, 5]");

// Conversion representing associative array with string
int[string] associativeArray = ["0":1, "1":2];
assert(to!string(associativeArray) == `["0":1, "1":2]` ||
       to!string(associativeArray) == `["1":2, "0":1]`);

// char* to string conversion
assert(to!string(cast(char*) null) == "");
assert(to!string("foo\0".ptr) == "foo");

// Conversion reinterpreting void array to string
auto w = "abcx"w;
const(void)[] b = w;
assert(b.length == 8);

auto c = to!(wchar[])(b);
assert(c == "abcx");
Strings can be converted to enum types. The enum member with the same name as the
input string is returned. The comparison is case-sensitive.
A ConvException is thrown if the enum does not have the specified member.
import std.exception : assertThrown;

enum E { a, b, c }
assert(to!E("a") == E.a);
assert(to!E("b") == E.b);
assertThrown!ConvException(to!E("A"));
to!double;
                continue;
            }
        }
        
(local variable) ulong ii++;
    }
    return 
(local variable) ulong cici == 3;
}

(alias) object.string = stringstring 
string platform_ui_portal_appearance.hexOf(in double[3] rgb) @safehexOf(in double[3] 
(parameter) const(double[3]) rgbrgb) @safe
    => 
string std.format.format!("#%02X%02X%02X", ubyte, ubyte, ubyte)(ubyte __param_0, ubyte __param_1, ubyte __param_2) pure @safe
Examples
The format string can be checked at compile-time:
auto s = format!"%s is %s"("Pi", 3.14);
assert(s == "Pi is 3.14");

// This line doesn't compile, because 3.14 cannot be formatted with %d:
// s = format!"%s is %d"("Pi", 3.14);
format!"#%02X%02X%02X"(
        cast(ubyte)(
(parameter) const(double[3]) rgbrgb[0] * 255 + 0.5),
        cast(ubyte)(
(parameter) const(double[3]) rgbrgb[1] * 255 + 0.5),
        cast(ubyte)(
(parameter) const(double[3]) rgbrgb[2] * 255 + 0.5));

/// The nine colors `AdwAccentColor` can hold, as `adw_accent_color_to_rgba`
/// defines them. GNOME's portal backend emits exactly one of these, so a match
/// here proves the quantization the deep-dive describes.
static immutable 
(immutable global) immutable(string[string]) platform_ui_portal_appearance.namedAccents
The nine colors AdwAccentColor can hold, as adw_accent_color_to_rgba
defines them. GNOME's portal backend emits exactly one of these, so a match
here proves the quantization the deep-dive describes.namedAccents = [
    "blue":   "#3584E4", "teal":   "#2190A4", "green":  "#3A944A",
    "yellow": "#C88800", "orange": "#ED5B00", "red":    "#E62D42",
    "pink":   "#D56199", "purple": "#9141AC", "slate":  "#6F8396",
];

void 
void D main() @safemain() @safe
{
    if (
(class) std.process.environment
Manipulates environment variables using an associative-array-like
interface.
This class contains only static methods, and cannot be instantiated.
See below for examples of use.environment.
string std.process.environment.get(scope const(char)[] name, string defaultValue = null) @safe
Retrieves the value of the environment variable with the given name,
or a default value if the variable doesn't exist.
Unlike environment.opIndex, this function never throws on Posix.
auto sh = environment.get("SHELL", "/bin/sh");
This function is also useful in checking for the existence of an
environment variable.
auto myVar = environment.get("MYVAR");
if (myVar is null)
{
    // Environment variable doesn't exist.
    // Note that we have to use 'is' for the comparison, since
    // myVar == null is also true if the variable exists but is
    // empty.
}
@paramname name of the environment variable to retrieve@paramdefaultValue default value to return if the environment variable doesn't exist.@returnsthe value of the environment variable if found, otherwise
null if the environment doesn't exist.@throwsUTFException if the variable contains invalid UTF-16
characters (Windows only).get("DBUS_SESSION_BUS_ADDRESS") is null)
    {
        
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("SKIP: no DBUS_SESSION_BUS_ADDRESS — no session bus to query.");
        return;
    }

    const 
(local variable) const(string) tooltool = 
string platform_ui_portal_appearance.findDbusTool() @safe
Locate a D-Bus command-line client. gdbus ships with GLib, busctl with
systemd; a desktop running a portal has at least one.findDbusTool();
    if (
(local variable) const(string) tooltool is null)
    {
        
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("SKIP: neither gdbus nor busctl on PATH.");
        return;
    }

    
void std.stdio.writefln!("desktop: XDG_CURRENT_DESKTOP=%s   (querying via %s)", string, string)(string __param_0, string __param_1) @safe
Equivalent to writef(fmt, args, '\n').writefln!"desktop: XDG_CURRENT_DESKTOP=%s   (querying via %s)"(
        
(class) std.process.environment
Manipulates environment variables using an associative-array-like
interface.
This class contains only static methods, and cannot be instantiated.
See below for examples of use.environment.
string std.process.environment.get(scope const(char)[] name, string defaultValue = null) @safe
Retrieves the value of the environment variable with the given name,
or a default value if the variable doesn't exist.
Unlike environment.opIndex, this function never throws on Posix.
auto sh = environment.get("SHELL", "/bin/sh");
This function is also useful in checking for the existence of an
environment variable.
auto myVar = environment.get("MYVAR");
if (myVar is null)
{
    // Environment variable doesn't exist.
    // Note that we have to use 'is' for the comparison, since
    // myVar == null is also true if the variable exists but is
    // empty.
}
@paramname name of the environment variable to retrieve@paramdefaultValue default value to return if the environment variable doesn't exist.@returnsthe value of the environment variable if found, otherwise
null if the environment doesn't exist.@throwsUTFException if the variable contains invalid UTF-16
characters (Windows only).get("XDG_CURRENT_DESKTOP", "(unset)"), 
(local variable) const(string) tooltool);

    // Interface version: `ReadOne` needs >= 2.
    const 
(local variable) const(std.typecons.Tuple!(int, "status", string, "output")) verver = 
(local variable) const(string) tooltool == "gdbus"
        ? 
std.typecons.Tuple!(int, "status", string, "output") std.process.execute(scope const(char[])[] args, const(string[string]) env = cast(const(string[string]))null, std.process.Config config = Config(Flags.none, null, null), ulong maxOutput = 18446744073709551615LU, scope const(char)[] workDir = null) @safe
Executes the given program or shell command and returns its exit
code and output.
execute and executeShell start a new process using
spawnProcess and spawnShell, respectively, and wait
for the process to complete before returning.  The functions capture
what the child process prints to both its standard output and
standard error streams, and return this together with its exit code.
auto dmd = execute(["dmd", "myapp.d"]);
if (dmd.status != 0) writeln("Compilation failed:\n", dmd.output);

auto ls = executeShell("ls -l");
if (ls.status != 0) writeln("Failed to retrieve file listing");
else writeln(ls.output);
The args/program/command, env and config
parameters are forwarded straight to the underlying spawn functions,
and we refer to their documentation for details.
POSIX specific
If the process is terminated by a signal, the status field of
the return value will contain a negative number whose absolute
value is the signal number.  (See wait for details.)
@paramargs An array which contains the program name as the zeroth element and any command-line arguments in the following elements. (See spawnProcess for details.)@paramprogram The program name, without command-line arguments. (See spawnProcess for details.)@paramcommand A shell command which is passed verbatim to the command interpreter. (See spawnShell for details.)@paramenv Additional environment variables for the child process. (See spawnProcess for details.)@paramconfig Flags that control process creation. See Config for an overview of available flags, and note that the retainStd... flags have no effect in this function.@parammaxOutput The maximum number of bytes of output that should be captured.@paramworkDir The working directory for the new process. By default the child process inherits the parent's working directory.@paramshellPath The path to the shell to use to run the specified program. By default this is nativeShell.@returnsAn std.typecons.Tuple!(int, "status", string, "output").@throws
ProcessException on failure to start the process.
StdioException on failure to capture output.execute([
            "gdbus", "call", "--session", "--dest", 
(constant) string platform_ui_portal_appearance.portalDest = "org.freedesktop.portal.Desktop"portalDest,
            "--object-path", 
(constant) string platform_ui_portal_appearance.portalPath = "/org/freedesktop/portal/desktop"portalPath, "--method",
            "org.freedesktop.DBus.Properties.Get",
            "org.freedesktop.portal.Settings", "version",
        ])
        : 
std.typecons.Tuple!(int, "status", string, "output") std.process.execute(scope const(char[])[] args, const(string[string]) env = cast(const(string[string]))null, std.process.Config config = Config(Flags.none, null, null), ulong maxOutput = 18446744073709551615LU, scope const(char)[] workDir = null) @safe
Executes the given program or shell command and returns its exit
code and output.
execute and executeShell start a new process using
spawnProcess and spawnShell, respectively, and wait
for the process to complete before returning.  The functions capture
what the child process prints to both its standard output and
standard error streams, and return this together with its exit code.
auto dmd = execute(["dmd", "myapp.d"]);
if (dmd.status != 0) writeln("Compilation failed:\n", dmd.output);

auto ls = executeShell("ls -l");
if (ls.status != 0) writeln("Failed to retrieve file listing");
else writeln(ls.output);
The args/program/command, env and config
parameters are forwarded straight to the underlying spawn functions,
and we refer to their documentation for details.
POSIX specific
If the process is terminated by a signal, the status field of
the return value will contain a negative number whose absolute
value is the signal number.  (See wait for details.)
@paramargs An array which contains the program name as the zeroth element and any command-line arguments in the following elements. (See spawnProcess for details.)@paramprogram The program name, without command-line arguments. (See spawnProcess for details.)@paramcommand A shell command which is passed verbatim to the command interpreter. (See spawnShell for details.)@paramenv Additional environment variables for the child process. (See spawnProcess for details.)@paramconfig Flags that control process creation. See Config for an overview of available flags, and note that the retainStd... flags have no effect in this function.@parammaxOutput The maximum number of bytes of output that should be captured.@paramworkDir The working directory for the new process. By default the child process inherits the parent's working directory.@paramshellPath The path to the shell to use to run the specified program. By default this is nativeShell.@returnsAn std.typecons.Tuple!(int, "status", string, "output").@throws
ProcessException on failure to start the process.
StdioException on failure to capture output.execute([
            "busctl", "--user", "get-property", 
(constant) string platform_ui_portal_appearance.portalDest = "org.freedesktop.portal.Desktop"portalDest, 
(constant) string platform_ui_portal_appearance.portalPath = "/org/freedesktop/portal/desktop"portalPath,
            "org.freedesktop.portal.Settings", "version",
        ]);
    if (
(local variable) const(std.typecons.Tuple!(int, "status", string, "output")) verver.status != 0)
    {
        
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("SKIP: org.freedesktop.portal.Settings is not available on this bus.");
        return;
    }
    uint 
(local variable) uint vv;
    if (
bool platform_ui_portal_appearance.parseUint(string raw, out uint value) @safe
Pull the first unsigned integer out of a gdbus/busctl reply.parseUint(
(local variable) const(std.typecons.Tuple!(int, "status", string, "output")) verver.output.
string std.string.strip!string(string str) pure nothrow @nogc @safe
Strips both leading and trailing whitespace (as defined by
isWhite) or as specified in the second argument.
Examples
import std.uni : lineSep, paraSep;
assert(strip("     hello world     ") ==
       "hello world");
assert(strip("\n\t\v\rhello world\n\t\v\r") ==
       "hello world");
assert(strip("hello world") ==
       "hello world");
assert(strip([lineSep] ~ "hello world" ~ [lineSep]) ==
       "hello world");
assert(strip([paraSep] ~ "hello world" ~ [paraSep]) ==
       "hello world");
@paramstr string or random access range of characters@paramchars string of characters to be stripped@paramleftChars string of leading characters to be stripped@paramrightChars string of trailing characters to be stripped@returnsslice of str stripped of leading and trailing whitespace
or characters as specified in the second argument.@seeGeneric stripping on ranges: stripstrip, 
(field) string std.typecons.Tuple!(int, "status", string, "output").__expand_field_1v))
        
void std.stdio.writefln!("portal Settings interface version: %d%s", uint, string)(uint __param_0, string __param_1) @safe
Equivalent to writef(fmt, args, '\n').writefln!"portal Settings interface version: %d%s"(
            
(local variable) uint vv, 
(local variable) uint vv >= 2 ? "" : "  (< 2: ReadOne unavailable)");
    
void std.stdio.writeln!()() @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln();

    
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("org.freedesktop.appearance:");

    uint 
(local variable) uint schemescheme = 0;
    bool 
(local variable) bool haveSchemehaveScheme;

    foreach (
(parameter) string keykey; ["color-scheme", "accent-color", "contrast", "reduced-motion"])
    {
        const 
(local variable) const(platform_ui_portal_appearance.KeyResult) resres = 
platform_ui_portal_appearance.KeyResult platform_ui_portal_appearance.readOne(string tool, string key) @safe
org.freedesktop.portal.Settings.ReadOne(namespace, key).
ReadOne — not Read. The spec marks Read deprecated because it
"returns the value wrapped in two variant layers instead of one"; ReadOne
was added in interface version 2.readOne(
(local variable) const(string) tooltool, 
(local variable) string keykey);
        if (!
(local variable) const(platform_ui_portal_appearance.KeyResult) resres.
(field) bool platform_ui_portal_appearance.KeyResult.ok
a value came backok)
        {
            
void std.stdio.writefln!("  %-14s %s", string, string)(string __param_0, string __param_1) @safe
Equivalent to writef(fmt, args, '\n').writefln!"  %-14s %s"(
(local variable) string keykey,
                
(local variable) const(platform_ui_portal_appearance.KeyResult) resres.
(field) bool platform_ui_portal_appearance.KeyResult.notFound
the backend does not implement this keynotFound
                    ? "NOT IMPLEMENTED by this backend (portal.Error.NotFound)"
                    : "error: " ~ 
(local variable) const(platform_ui_portal_appearance.KeyResult) resres.
(field) string platform_ui_portal_appearance.KeyResult.raw
verbatim reply (or error text)raw);
            continue;
        }

        if (
(local variable) string keykey == "accent-color")
        {
            double[3] 
(local variable) double[3] rgbrgb;
            if (
bool platform_ui_portal_appearance.parseAccent(string raw, out double[3] rgb) @safe
Pull the three doubles of an (ddd) accent reply.parseAccent(
(local variable) const(platform_ui_portal_appearance.KeyResult) resres.
(field) string platform_ui_portal_appearance.KeyResult.raw
verbatim reply (or error text)raw, 
(local variable) double[3] rgbrgb))
            {
                // Out-of-range means "unset", per the spec.
                const 
(local variable) const(bool) unsetunset = 
(local variable) double[3] rgbrgb[0] < 0 || 
(local variable) double[3] rgbrgb[0] > 1 || 
(local variable) double[3] rgbrgb[1] < 0 || 
(local variable) double[3] rgbrgb[1] > 1
                    || 
(local variable) double[3] rgbrgb[2] < 0 || 
(local variable) double[3] rgbrgb[2] > 1;
                if (
(local variable) const(bool) unsetunset)
                    
void std.stdio.writefln!("  %-14s unset (out of [0,1])", string)(string __param_0) @safe
Equivalent to writef(fmt, args, '\n').writefln!"  %-14s unset (out of [0,1])"(
(local variable) string keykey);
                else
                {
                    const 
(local variable) const(string) hexhex = 
string platform_ui_portal_appearance.hexOf(in double[3] rgb) @safehexOf(
(local variable) double[3] rgbrgb);
                    
(alias) object.string = stringstring 
(local variable) string namednamed = "not one of AdwAccentColor's nine";
                    foreach (
int core.internal.newaa._d_aaApply2!(string, immutable(string), int delegate(ref string, ref immutable(string)) pure nothrow @safe)(immutable(string[string]) a, int delegate(ref string, ref immutable(string)) pure nothrow @safe dg) pure nothrow @safename, 
(parameter) immutable(string) valuevalue; 
(immutable global) immutable(string[string]) platform_ui_portal_appearance.namedAccents
The nine colors AdwAccentColor can hold, as adw_accent_color_to_rgba
defines them. GNOME's portal backend emits exactly one of these, so a match
here proves the quantization the deep-dive describes.namedAccents)
                        if (
(local variable) immutable(string) valuevalue == 
(local variable) const(string) hexhex)
                            
(local variable) string namednamed = "= AdwAccentColor '" ~ 
(local variable) string namename ~ "'";
                    
void std.stdio.writefln!("  %-14s %s  (%.4f, %.4f, %.4f)  %s", string, string, double, double, double, string)(string __param_0, string __param_1, double __param_2, double __param_3, double __param_4, string __param_5) @safe
Equivalent to writef(fmt, args, '\n').writefln!"  %-14s %s  (%.4f, %.4f, %.4f)  %s"(
                        
(local variable) string keykey, 
(local variable) const(string) hexhex, 
(local variable) double[3] rgbrgb[0], 
(local variable) double[3] rgbrgb[1], 
(local variable) double[3] rgbrgb[2], 
(local variable) string namednamed);
                }
            }
            else
                
void std.stdio.writefln!("  %-14s unparsed: %s", string, string)(string __param_0, string __param_1) @safe
Equivalent to writef(fmt, args, '\n').writefln!"  %-14s unparsed: %s"(
(local variable) string keykey, 
(local variable) const(platform_ui_portal_appearance.KeyResult) resres.
(field) string platform_ui_portal_appearance.KeyResult.raw
verbatim reply (or error text)raw);
            continue;
        }

        uint 
(local variable) uint valuevalue;
        if (!
bool platform_ui_portal_appearance.parseUint(string raw, out uint value) @safe
Pull the first unsigned integer out of a gdbus/busctl reply.parseUint(
(local variable) const(platform_ui_portal_appearance.KeyResult) resres.
(field) string platform_ui_portal_appearance.KeyResult.raw
verbatim reply (or error text)raw, 
(local variable) uint valuevalue))
        {
            
void std.stdio.writefln!("  %-14s unparsed: %s", string, string)(string __param_0, string __param_1) @safe
Equivalent to writef(fmt, args, '\n').writefln!"  %-14s unparsed: %s"(
(local variable) string keykey, 
(local variable) const(platform_ui_portal_appearance.KeyResult) resres.
(field) string platform_ui_portal_appearance.KeyResult.raw
verbatim reply (or error text)raw);
            continue;
        }

        
(alias) object.string = stringstring 
(local variable) string meaningmeaning;
        final switch (
(local variable) string keykey)
        {
        case "color-scheme":
            
(local variable) string meaningmeaning = 
(local variable) uint valuevalue == 1 ? "prefer-dark" : 
(local variable) uint valuevalue == 2 ? "prefer-light"
                : "no preference";
            
(local variable) uint schemescheme = 
(local variable) uint valuevalue;
            
(local variable) bool haveSchemehaveScheme = true;
            break;
        case "contrast":
            
(local variable) string meaningmeaning = 
(local variable) uint valuevalue == 1 ? "higher contrast" : "normal";
            break;
        case "reduced-motion":
            
(local variable) string meaningmeaning = 
(local variable) uint valuevalue == 1 ? "reduced" : "no preference";
            break;
        }
        
void std.stdio.writefln!("  %-14s %d  (%s)", string, uint, string)(string __param_0, uint __param_1, string __param_2) @safe
Equivalent to writef(fmt, args, '\n').writefln!"  %-14s %d  (%s)"(
(local variable) string keykey, 
(local variable) uint valuevalue, 
(local variable) string meaningmeaning);
    }

    
void std.stdio.writeln!()() @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln();
    if (
(local variable) bool haveSchemehaveScheme)
        // 0 means "no preference", NOT "light": the application's own default
        // wins there. Collapsing 0 into light is the single most common bug in
        // portal consumers — see ../index.md § "Three values, not two".
        
void std.stdio.writefln!("=> theme to use: %s", string)(string __param_0) @safe
Equivalent to writef(fmt, args, '\n').writefln!"=> theme to use: %s"(
            
(local variable) uint schemescheme == 1 ? "the app's dark theme"
                : 
(local variable) uint schemescheme == 2 ? "the app's light theme"
                : "the app's OWN default (0 = no preference, not light)");

    
void std.stdio.writeln!()() @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln();
    
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("Change notification is the SettingChanged(namespace, key, value) signal;");
    
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("watch it with:");
    
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("  gdbus monitor --session --dest org.freedesktop.portal.Desktop");
    
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("then change the system appearance. Note that a desktop running more");
    
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("than one portal backend emits the signal MORE THAN ONCE per change,");
    
void std.stdio.writeln!string(string __param_0) @safe
Equivalent to write(args, '\n').  Calling writeln without
arguments is valid and just prints a newline to the standard
output.
Example
Reads stdin and writes it to stdout with an argument
counter.
import std.stdio;

void main()
{
    string line;

    for (size_t count = 0; (line = readln) !is null; count++)
    {
         writeln("Input ", count, ": ", line);
    }
}
@paramargs the items to write to stdout@throwsIn case of an I/O error, throws an StdioException.writeln("so compare against the value you already hold before repainting.");
}