Indexed

This struct takes two ranges, source and indices, and creates a view of source as if its elements were reordered according to indices. indices may include only a subset of the elements of source and may also repeat elements.

Source must be a random access range. The returned range will be bidirectional or random-access if Indices is bidirectional or random-access, respectively.

struct Indexed (

Source

Indices

) if (

isRandomAccessRange!Source &&

isInputRange!Indices

is(typeof(Source.init[ElementType!(Indices).init]))

) {

auto ref front [@property getter];

void popFront();

static if(isInfinite!Indices)

enum bool empty;

static if(!(isInfinite!Indices))

bool empty [@property getter];

static if(isForwardRange!Indices)

typeof(this) save [@property getter];

static if(hasAssignableElements!Source)

ElementType!Source front [@property setter];

static if(hasMobileElements!Source)

auto moveFront();

static if(isBidirectionalRange!Indices)

auto ref back [@property getter];

static if(isBidirectionalRange!Indices)

void popBack();

static if(isBidirectionalRange!Indices)
static if(hasAssignableElements!Source)

ElementType!Source back [@property setter];

static if(isBidirectionalRange!Indices)
static if(hasMobileElements!Source)

auto moveBack();

static if(isRandomAccessRange!Indices)

auto ref opIndex(size_t index);

static if(isRandomAccessRange!Indices)
static if(hasSlicing!Indices)

typeof(this) opSlice(size_t a, size_t b);

static if(isRandomAccessRange!Indices)
static if(hasAssignableElements!Source)

auto opIndexAssign(ElementType!Source newVal, size_t index);

static if(isRandomAccessRange!Indices)
static if(hasMobileElements!Source)

auto moveAt(size_t index);

Source source [@property getter];

Indices indices [@property getter];

static if(isRandomAccessRange!Indices)

size_t physicalIndex(size_t logicalIndex);

}

Members

Functions

moveAt auto moveAt(size_t index)
moveBack auto moveBack()
moveFront auto moveFront()
opIndex auto ref opIndex(size_t index)
opIndexAssign auto opIndexAssign(ElementType!Source newVal, size_t index)
opSlice typeof(this) opSlice(size_t a, size_t b): Range primitives
physicalIndex size_t physicalIndex(size_t logicalIndex): Returns the physical index into the source range corresponding to a given logical index. This is useful, for example, when indexing an Indexed without adding another layer of indirection.
popBack void popBack()
popFront void popFront()
back auto ref back [@property getter]
ElementType!Source back [@property setter]
empty bool empty [@property getter]: Range primitives

Properties

front auto ref front [@property getter]
ElementType!Source front [@property setter]: Range primitives
indices Indices indices [@property getter]: Returns the indices range.
save typeof(this) save [@property getter]: Range primitives
source Source source [@property getter]: Returns the source range.

Examples

import std.algorithm.comparison : equal;
auto source = [1, 2, 3, 4, 5];
auto indices = [4, 3, 1, 2, 0, 4];
auto ind = indexed(source, indices);
assert(equal(ind, [5, 4, 2, 3, 1, 5]));
assert(equal(retro(ind), [5, 1, 3, 2, 4, 5]));