View source code Display the source code in std/range/primitives.d from which this page was generated on github. Improve this page Quickly fork, edit online, and submit a pull request for this page. Requires a signed-in GitHub account. This works well for small changes. If you'd like to make larger changes you may want to consider using local clone. Page wiki View or edit the community-maintained wiki page associated with this page.

Template std.range.primitives.ElementType

The element type of R. R does not have to be a range. The element type is determined as the type yielded by r.front for an object r of type R. For example, ElementType!(T[]) is T if T[] isn't a narrow string; if it is, the element type is dchar. If R doesn't have front, ElementType!R is void.

Arguments

template ElementType(R);

Example

import std.range : iota;

// Standard arrays: returns the type of the elements of the array
static assert(is(ElementType!(int[]) == int));

// Accessing .front retrieves the decoded dchar
static assert(is(ElementType!(char[])  == dchar)); // rvalue
static assert(is(ElementType!(dchar[]) == dchar)); // lvalue

// Ditto
static assert(is(ElementType!(string) == dchar));
static assert(is(ElementType!(dstring) == immutable(dchar)));

// For ranges it gets the type of .front.
auto range = iota(0, 10);
static assert(is(ElementType!(typeof(range)) == int));

Authors

Andrei Alexandrescu, David Simcha, and Jonathan M Davis. Credit for some of the ideas in building this module goes to Leonardo Maffi.

License

Boost License 1.0.

Comments