Function some
Type constructor for an optional having some value of T
auto some(T)
(
auto ref T value
);
Example
import std .range: only;
import std .algorithm: equal;
auto a = no!int;
assert(a == none);
a = 9;
assert(a == some(9));
assert(a != none);
import std .algorithm: map;
assert(only(1, 2, 3) .map!some .equal(only(some(1), some(2), some(3))));