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std.array
Functions and types that manipulate built-in arrays and associative arrays.
This module provides all kinds of functions to create, manipulate or convert arrays:
Function Name | Description |
---|---|
array | Returns a copy of the input in a newly allocated dynamic array. |
appender | Returns a new Appender or RefAppender initialized with a given array. |
assocArray | Returns a newly allocated associative array from a range of key/value tuples. |
byPair | Construct a range iterating over an associative array by key/value tuples. |
insertInPlace | Inserts into an existing array at a given position. |
join | Concatenates a range of ranges into one array. |
minimallyInitializedArray | Returns a new array of type T. |
replace | Returns a new array with all occurrences of a certain subrange replaced. |
replaceFirst | Returns a new array with the first occurrence of a certain subrange replaced. |
replaceInPlace | Replaces all occurrences of a certain subrange and puts the result into a given array. |
replaceInto | Replaces all occurrences of a certain subrange and puts the result into an output range. |
replaceLast | Returns a new array with the last occurrence of a certain subrange replaced. |
replaceSlice | Returns a new array with a given slice replaced. |
replicate | Creates a new array out of several copies of an input array or range. |
sameHead | Checks if the initial segments of two arrays refer to the same place in memory. |
sameTail | Checks if the final segments of two arrays refer to the same place in memory. |
split | Eagerly split a range or string into an array. |
uninitializedArray | Returns a new array of type T without initializing its elements. |
License:
Authors:
Andrei Alexandrescu and Jonathan M Davis
Source std/array.d
- ForeachType!Range[]
array
(Range)(Ranger
)
if (isIterable!Range && !isNarrowString!Range && !isInfinite!Range);
ForeachType!(PointerTarget!Range)[]array
(Range)(Ranger
)
if (isPointer!Range && isIterable!(PointerTarget!Range) && !isNarrowString!Range && !isInfinite!Range); - Allocates an
array
and initializes it with copies of the elements of ranger
.Narrow strings are handled as a special case in an overload.Parameters:Range r
range (or aggregate with opApply function) whose elements are copied into the allocated array
Returns:allocated and initializedarray
Examples:auto a = array([1, 2, 3, 4, 5][]); writeln(a); // [1, 2, 3, 4, 5]
- @trusted ElementType!String[]
array
(String)(scope Stringstr
)
if (isNarrowString!String); - Convert a narrow string to an
array
type that fully supports random access. This is handled as a special case and always returns anarray
of dcharParameters:String str
isNarrowString to be converted to an array
of dcharReturns:a dchar[], const(dchar)[], or immutable(dchar)[] depending on the constness of the input.Examples:import std.range.primitives : isRandomAccessRange; writeln("Hello D".array); // "Hello D"d static assert(isRandomAccessRange!string == false); writeln("Hello D"w.array); // "Hello D"d static assert(isRandomAccessRange!dstring == true);
- auto
assocArray
(Range)(Ranger
)
if (isInputRange!Range); - Returns a newly allocated associative array from a range of key/value tuples.Parameters:
Range r
An input range of tuples of keys and values. Returns:A newly allocated associative array out of elements of the input range, which must be a range of tuples (Key, Value). Returns anull
associative array reference when given an empty range.Duplicates Associative arrays have unique keys. If
r
contains duplicate keys, then the result will contain the value of the last pair for that key inr
.See Also:Examples:import std.range; import std.typecons; auto a = assocArray(zip([0, 1, 2], ["a", "b", "c"])); // aka zipMap assert(is(typeof(a) == string[int])); writeln(a); // [0:"a", 1:"b", 2:"c"] auto b = assocArray([ tuple("foo", "bar"), tuple("baz", "quux") ]); assert(is(typeof(b) == string[string])); writeln(b); // ["foo":"bar", "baz":"quux"]
- auto
byPair
(AA : Value[Key], Value, Key)(AAaa
); - Construct a range iterating over an associative array by key/value tuples.Parameters:
AA aa
The associative array to iterate over. Returns:A forward range of Tuple's of key and value pairs from the given associative array. The members of each pair can be accessed by name (.key and .value). or by integer index (0 and 1 respectively).Examples:import std.algorithm.sorting : sort; import std.typecons : tuple, Tuple; auto aa = ["a": 1, "b": 2, "c": 3]; Tuple!(string, int)[] pairs; // Iteration over key/value pairs. foreach (pair; aa.byPair) { if (pair.key == "b") pairs ~= tuple("B", pair.value); else pairs ~= pair; } // Iteration order is implementation-dependent, so we should sort it to get // a fixed order. pairs.sort(); assert(pairs == [ tuple("B", 2), tuple("a", 1), tuple("c", 3) ]);
- nothrow @system auto
uninitializedArray
(T, I...)(Isizes
)
if (isDynamicArray!T && allSatisfy!(isIntegral, I) && hasIndirections!(ElementEncodingType!T));
nothrow @trusted autouninitializedArray
(T, I...)(Isizes
)
if (isDynamicArray!T && allSatisfy!(isIntegral, I) && !hasIndirections!(ElementEncodingType!T)); - Returns a new array of type T allocated on the garbage collected heap without initializing its elements. This can be a useful optimization if every element will be immediately initialized. T may be a multidimensional array. In this case
sizes
may be specified for any number of dimensions from 0 to the number in T.uninitializedArray
is nothrow and weakly pure.uninitializedArray
is @system if the uninitialized element type has pointers.Examples:double[] arr = uninitializedArray!(double[])(100); writeln(arr.length); // 100 double[][] matrix = uninitializedArray!(double[][])(42, 31); writeln(matrix.length); // 42 writeln(matrix[0].length); // 31 char*[] ptrs = uninitializedArray!(char*[])(100); writeln(ptrs.length); // 100
- nothrow @trusted auto
minimallyInitializedArray
(T, I...)(Isizes
)
if (isDynamicArray!T && allSatisfy!(isIntegral, I)); - Returns a new array of type T allocated on the garbage collected heap.Partial initialization is done for types with indirections, for preservation of memory safety. Note that elements will only be initialized to 0, but not necessarily the element type's .init.
minimallyInitializedArray
is nothrow and weakly pure.Examples:import std.algorithm.comparison : equal; import std.range : repeat; auto arr = minimallyInitializedArray!(int[])(42); writeln(arr.length); // 42 // Elements aren't necessarily initialized to 0 assert(!arr.equal(0.repeat(42)));
- @trusted CommonType!(T[], U[])
overlap
(T, U)(T[]a
, U[]b
)
if (is(typeof(a
.ptr <b
.ptr) == bool)); - Returns the overlapping portion, if any, of two arrays. Unlike equal,
overlap
only compares the pointers and lengths in the ranges, not the values referred by them. If r1 and r2 have an overlapping slice, returns that slice. Otherwise, returns thenull
slice.Examples:int[] a = [ 10, 11, 12, 13, 14 ]; int[] b = a[1 .. 3]; writeln(overlap(a, b)); // [11, 12] b = b.dup; // overlap disappears even though the content is the same assert(overlap(a, b).empty); static test()() @nogc { auto a = "It's three o'clock"d; auto b = a[5 .. 10]; return b.overlap(a); } //works at compile-time static assert(test == "three"d);
- void
insertInPlace
(T, U...)(ref T[]array
, size_tpos
, Ustuff
)
if (!isSomeString!(T[]) && allSatisfy!(isInputRangeOrConvertible!T, U) && (U.length > 0));
voidinsertInPlace
(T, U...)(ref T[]array
, size_tpos
, Ustuff
)
if (isSomeString!(T[]) && allSatisfy!(isCharOrStringOrDcharRange, U)); - Inserts
stuff
(which must be an input range or any number of implicitly convertible items) inarray
at positionpos
.Parameters:T[] array
The array
thatstuff
will be inserted into.size_t pos
The position in array
to insert thestuff
.U stuff
An input range, or any number of implicitly convertible items to insert into array
.Examples:int[] a = [ 1, 2, 3, 4 ]; a.insertInPlace(2, [ 1, 2 ]); writeln(a); // [1, 2, 1, 2, 3, 4] a.insertInPlace(3, 10u, 11); writeln(a); // [1, 2, 1, 10, 11, 2, 3, 4]
- pure nothrow @safe bool
sameHead
(T)(in T[]lhs
, in T[]rhs
); - Returns whether the fronts of
lhs
andrhs
both refer to the same place in memory, making one of the arrays a slice of the other which starts at index 0.Examples:auto a = [1, 2, 3, 4, 5]; auto b = a[0 .. 2]; assert(a.sameHead(b));
- pure nothrow @trusted bool
sameTail
(T)(in T[]lhs
, in T[]rhs
); - Returns whether the backs of
lhs
andrhs
both refer to the same place in memory, making one of the arrays a slice of the other which end at index $.Examples:auto a = [1, 2, 3, 4, 5]; auto b = a[3..$]; assert(a.sameTail(b));
- ElementEncodingType!S[]
replicate
(S)(Ss
, size_tn
)
if (isDynamicArray!S);
ElementType!S[]replicate
(S)(Ss
, size_tn
)
if (isInputRange!S && !isDynamicArray!S); - Parameters:
S s
an input range or a dynamic array size_t n
number of times to repeat s
Returns:An array that consists ofs
repeatedn
times. This function allocates, fills, and returns a new array.See Also:For a lazy version, refer to std.range.repeat.Examples:auto a = "abc"; auto s = replicate(a, 3); writeln(s); // "abcabcabc" auto b = [1, 2, 3]; auto c = replicate(b, 3); writeln(c); // [1, 2, 3, 1, 2, 3, 1, 2, 3] auto d = replicate(b, 0); writeln(d); // []
- pure @safe S[]
split
(S)(Ss
)
if (isSomeString!S);
autosplit
(Range, Separator)(Rangerange
, Separatorsep
)
if (isForwardRange!Range && (is(typeof(ElementType!Range.init == Separator.init)) || is(typeof(ElementType!Range.init == ElementType!Separator.init)) && isForwardRange!Separator));
autosplit
(alias isTerminator, Range)(Rangerange
)
if (isForwardRange!Range && is(typeof(unaryFun!isTerminator(range
.front)))); - Eagerly splits
range
into an array, usingsep
as the delimiter.When no delimiter is provided, strings aresplit
into an array of words, using whitespace as delimiter. Runs of whitespace are merged together (no empty words are produced). Therange
must be a forward range. The separator can be a value of the same type as the elements inrange
or it can be another forwardrange
.Parameters:S s
the string to split
by word if no separator is givenRange range
the range
tosplit
Separator sep
a value of the same type as the elements of range
or anotherReturns:An array containing the divided parts ofrange
(or the words ofs
).See Also:std.algorithm.iteration.splitter for a lazy version without allocating memory. std.regex.splitter for a version that splits using a regular expression defined separator.Examples:import std.uni : isWhite; writeln("Learning,D,is,fun".split(",")); // ["Learning", "D", "is", "fun"] writeln("Learning D is fun".split!isWhite); // ["Learning", "D", "is", "fun"] writeln("Learning D is fun".split(" D ")); // ["Learning", "is fun"]
Examples:string str = "Hello World!"; writeln(str.split); // ["Hello", "World!"] string str2 = "Hello\t\tWorld\t!"; writeln(str2.split); // ["Hello", "World", "!"]
Examples:writeln(split("hello world")); // ["hello", "world"] writeln(split("192.168.0.1", ".")); // ["192", "168", "0", "1"] auto a = split([1, 2, 3, 4, 5, 1, 2, 3, 4, 5], [2, 3]); writeln(a); // [[1], [4, 5, 1], [4, 5]]
- ElementEncodingType!(ElementType!RoR)[]
join
(RoR, R)(RoRror
, scope Rsep
)
if (isInputRange!RoR && isInputRange!(Unqual!(ElementType!RoR)) && isInputRange!R && is(Unqual!(ElementType!(ElementType!RoR)) == Unqual!(ElementType!R)));
ElementEncodingType!(ElementType!RoR)[]join
(RoR, E)(RoRror
, scope Esep
)
if (isInputRange!RoR && isInputRange!(Unqual!(ElementType!RoR)) && is(E : ElementType!(ElementType!RoR)));
ElementEncodingType!(ElementType!RoR)[]join
(RoR)(RoRror
)
if (isInputRange!RoR && isInputRange!(Unqual!(ElementType!RoR))); - Eagerly concatenates all of the ranges in
ror
together (with the GC) into one array usingsep
as the separator if present.Parameters:RoR ror
An input range of input ranges R sep
An input range, or a single element, to join
the ranges onReturns:An array of elementsSee Also:For a lazy version, see std.algorithm.iteration.joinerExamples:writeln(join(["hello", "silly", "world"], " ")); // "hello silly world" writeln(join(["hello", "silly", "world"])); // "hellosillyworld" writeln(join([[1, 2, 3], [4, 5]], [72, 73])); // [1, 2, 3, 72, 73, 4, 5] writeln(join([[1, 2, 3], [4, 5]])); // [1, 2, 3, 4, 5] const string[] arr = ["apple", "banana"]; writeln(arr.join(",")); // "apple,banana" writeln(arr.join()); // "applebanana"
- E[]
replace
(E, R1, R2)(E[]subject
, R1from
, R2to
)
if (isDynamicArray!(E[]) && isForwardRange!R1 && isForwardRange!R2 && (hasLength!R2 || isSomeString!R2));
voidreplaceInto
(E, Sink, R1, R2)(Sinksink
, E[]subject
, R1from
, R2to
)
if (isOutputRange!(Sink, E) && isDynamicArray!(E[]) && isForwardRange!R1 && isForwardRange!R2 && (hasLength!R2 || isSomeString!R2)); - Replace occurrences of
from
withto
insubject
in a new array. Ifsink
is defined, then output the new array intosink
.Parameters:Sink sink
an output range E[] subject
the array to
scanR1 from
the item to
replace
R2 to
the item to
replace
all instances offrom
withReturns:Ifsink
isn't defined, a new array without changing the contents ofsubject
, or the original array if no match is found.See Also:std.algorithm.iteration.substitute for a lazyreplace
.Examples:writeln("Hello Wörld".replace("o Wö", "o Wo")); // "Hello World" writeln("Hello Wörld".replace("l", "h")); // "Hehho Wörhd"
Examples:auto arr = [1, 2, 3, 4, 5]; auto from = [2, 3]; auto to = [4, 6]; auto sink = appender!(int[])(); replaceInto(sink, arr, from, to); writeln(sink.data); // [1, 4, 6, 4, 5]
- T[]
replace
(T, Range)(T[]subject
, size_tfrom
, size_tto
, Rangestuff
)
if (isInputRange!Range && (is(ElementType!Range : T) || isSomeString!(T[]) && is(ElementType!Range : dchar))); - Replaces elements
from
array with indices rangingfrom
from
(inclusive)to
to
(exclusive) with the rangestuff
.Parameters:T[] subject
the array to
scansize_t from
the starting index size_t to
the ending index Range stuff
the items to
replace
in-betweenfrom
andto
Returns:A new array without changing the contents ofsubject
.See Also:std.algorithm.iteration.substitute for a lazyreplace
.Examples:auto a = [ 1, 2, 3, 4 ]; auto b = a.replace(1, 3, [ 9, 9, 9 ]); writeln(a); // [1, 2, 3, 4] writeln(b); // [1, 9, 9, 9, 4]
- void
replaceInPlace
(T, Range)(ref T[]array
, size_tfrom
, size_tto
, Rangestuff
)
if (is(typeof(replace(array
,from
,to
,stuff
)))); - Replaces elements
from
array
with indices rangingfrom
from
(inclusive)to
to
(exclusive) with the rangestuff
. Expands or shrinks thearray
as needed.Parameters:T[] array
the array to
scansize_t from
the starting index size_t to
the ending index Range stuff
the items to
replace in-betweenfrom
andto
Examples:int[] a = [1, 4, 5]; replaceInPlace(a, 1u, 2u, [2, 3, 4]); writeln(a); // [1, 2, 3, 4, 5] replaceInPlace(a, 1u, 2u, cast(int[])[]); writeln(a); // [1, 3, 4, 5] replaceInPlace(a, 1u, 3u, a[2 .. 4]); writeln(a); // [1, 4, 5, 5]
- E[]
replaceFirst
(E, R1, R2)(E[]subject
, R1from
, R2to
)
if (isDynamicArray!(E[]) && isForwardRange!R1 && is(typeof(appender!(E[])().put(from
[0..1]))) && isForwardRange!R2 && is(typeof(appender!(E[])().put(to
[0..1])))); - Replaces the first occurrence of
from
withto
insubject
.Parameters:E[] subject
the array to
scanR1 from
the item to
replaceR2 to
the item to
replacefrom
withReturns:A new array without changing the contents ofsubject
, or the original array if no match is found.Examples:auto a = [1, 2, 2, 3, 4, 5]; auto b = a.replaceFirst([2], [1337]); writeln(b); // [1, 1337, 2, 3, 4, 5] auto s = "This is a foo foo list"; auto r = s.replaceFirst("foo", "silly"); writeln(r); // "This is a silly foo list"
- E[]
replaceLast
(E, R1, R2)(E[]subject
, R1from
, R2to
)
if (isDynamicArray!(E[]) && isForwardRange!R1 && is(typeof(appender!(E[])().put(from
[0..1]))) && isForwardRange!R2 && is(typeof(appender!(E[])().put(to
[0..1])))); - Replaces the last occurrence of
from
withto
insubject
.Parameters:E[] subject
the array to
scanR1 from
the item to
replaceR2 to
the item to
replacefrom
withReturns:A new array without changing the contents ofsubject
, or the original array if no match is found.Examples:auto a = [1, 2, 2, 3, 4, 5]; auto b = a.replaceLast([2], [1337]); writeln(b); // [1, 2, 1337, 3, 4, 5] auto s = "This is a foo foo list"; auto r = s.replaceLast("foo", "silly"); writeln(r); // "This is a foo silly list"
- inout(T)[]
replaceSlice
(T)(inout(T)[]s
, in T[]slice
, in T[]replacement
); - Creates a new array such that the items in
slice
are replaced with the items inreplacement
.slice
andreplacement
do not need to be the same length. The result will grow or shrink based on the items given.Parameters:inout(T)[] s
the base of the new array T[] slice
the slice
ofs
to be replacedT[] replacement
the items to replace slice
withReturns:A new array that iss
withslice
replaced byreplacement
[].See Also:std.algorithm.iteration.substitute for a lazy replace.Examples:auto a = [1, 2, 3, 4, 5]; auto b = replaceSlice(a, a[1 .. 4], [0, 0, 0]); writeln(b); // [1, 0, 0, 0, 5]
- struct
Appender
(A) if (isDynamicArray!A); - Implements an output range that appends data to an array. This is recommended over array ~= data when appending many elements because it is more efficient.
Appender
maintains its own array metadata locally, so it can avoid global locking for each append where capacity is non-zero.See Also:Examples:auto app = appender!string(); string b = "abcdefg"; foreach (char c; b) app.put(c); writeln(app.data); // "abcdefg" int[] a = [ 1, 2 ]; auto app2 = appender(a); app2.put(3); app2.put([ 4, 5, 6 ]); writeln(app2.data); // [1, 2, 3, 4, 5, 6]
- pure nothrow @trusted this(A
arr
); - Constructs an Appender with a given array. Note that this does not copy the data. If the array has a larger capacity as determined by
arr
.capacity, it will be used by the appender. After initializing an appender on an array, appending to the original array will reallocate. - pure nothrow @safe void
reserve
(size_tnewCapacity
); - Reserve at least
newCapacity
elements for appending. Note that more elements may be reserved than requested. IfnewCapacity
<= capacity, then nothing is done. - const pure nothrow @property @safe size_t
capacity
(); - Returns:the
capacity
of the array (the maximum number of elements the managed array can accommodate before triggering a reallocation). If any appending will reallocate, 0 will be returned. - inout pure nothrow @property @trusted inout(ElementEncodingType!A)[]
data
(); - Returns:The managed array.
- void
put
(U)(Uitem
)
if (canPutItem!U); - Appends
item
to the managed array. - void
put
(Range)(Rangeitems
)
if (canPutRange!Range); - Appends an entire range to the managed array.
- void
opOpAssign
(string op : "~", U)(Urhs
)
if (__traits(compiles, put(rhs
))); - Appends
rhs
to the managed array.Parameters:U rhs
Element or range. - pure nothrow @trusted void
clear
(); - Clears the managed array. This allows the elements of the array to be reused for appending.
Note
clear
is disabled for immutable or const element types, due to the possibility that Appender might overwrite immutable data. - pure @trusted void
shrinkTo
(size_tnewlength
); - Shrinks the managed array to the given length.Throws:Exception if
newlength
is greater than the current array length.Note
shrinkTo
is disabled for immutable or const element types.
- struct
RefAppender
(A) if (isDynamicArray!A); - A version of Appender that can update an array in-place. It forwards all calls to an underlying appender implementation. Any calls made to the appender also update the pointer to the original array passed in.
Tip Use the arrayPtr overload of appender for construction with type-inference.
Examples:int[] a = [1, 2]; auto app2 = appender(&a); writeln(app2.data); // [1, 2] writeln(a); // [1, 2] app2 ~= 3; app2 ~= [4, 5, 6]; writeln(app2.data); // [1, 2, 3, 4, 5, 6] writeln(a); // [1, 2, 3, 4, 5, 6] app2.reserve(5); assert(app2.capacity >= 5);
- this(A*
arr
); - Constructs a RefAppender with a given array reference. This does not copy the data. If the array has a larger capacity as determined by
arr
.capacity, it will be used by the appender.Note Do not use built-in appending (i.e. ~=) on the original array until you are done with the appender, because subsequent calls to the appender will reallocate the array data without those appends.
Parameters:A* arr
Pointer to an array. Must not be null. - void
opDispatch
(string fn, Args...)(Argsargs
)
if (__traits(compiles, (Appender!A a) => mixin("a." ~ fn ~ "(args
)"))); - Wraps remaining Appender methods such as put.Parameters:
fn Method name to call. Args args
Arguments to pass to the method. - void
opOpAssign
(string op : "~", U)(Urhs
)
if (__traits(compiles, (Appender!A a) { a.put(rhs
); } )); - Appends
rhs
to the managed array.Parameters:U rhs
Element or range. - const @property size_t
capacity
(); - Returns the
capacity
of the array (the maximum number of elements the managed array can accommodate before triggering a reallocation). If any appending will reallocate,capacity
returns 0. - inout @property inout(ElementEncodingType!A)[]
data
(); - Returns the managed array.
- Appender!A
appender
(A)()
if (isDynamicArray!A);
Appender!(E[])appender
(A : E[], E)(auto ref Aarray
); - Convenience function that returns an Appender instance, optionally initialized with
array
.Examples:auto w = appender!string; // pre-allocate space for at least 10 elements (this avoids costly reallocations) w.reserve(10); assert(w.capacity >= 10); w.put('a'); // single elements w.put("bc"); // multiple elements // use the append syntax w ~= 'd'; w ~= "ef"; writeln(w.data); // "abcdef"
- RefAppender!(E[])
appender
(P : E[]*, E)(ParrayPtr
); - Convenience function that returns a RefAppender instance initialized with
arrayPtr
. Don't usenull
for the array pointer, use the other version ofappender
instead.Examples:int[] a = [1, 2]; auto app2 = appender(&a); writeln(app2.data); // [1, 2] writeln(a); // [1, 2] app2 ~= 3; app2 ~= [4, 5, 6]; writeln(app2.data); // [1, 2, 3, 4, 5, 6] writeln(a); // [1, 2, 3, 4, 5, 6] app2.reserve(5); assert(app2.capacity >= 5);
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