1 import std.range : iota;
2
3 // Standard arrays: returns the type of the elements of the array
4 static assert(is(ElementType!(int[]) == int));
5
6 // Accessing .front retrieves the decoded dchar
7 static assert(is(ElementType!(char[]) == dchar)); // rvalue
8 static assert(is(ElementType!(dchar[]) == dchar)); // lvalue
9
10 // Ditto
11 static assert(is(ElementType!(string) == dchar));
12 static assert(is(ElementType!(dstring) == immutable(dchar)));
13
14 // For ranges it gets the type of .front.
15 auto range = iota(0, 10);
16 static assert(is(ElementType!(typeof(range)) == int));
The D Programming Language's Unofficial Docs
beta
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.