Function toOptional
Converts a range or Nullable to an optional type
auto toOptional(R)
(
auto ref R range
)
if (from .std .range .isInputRange!R);
auto toOptional(T)
(
auto inout ref Nullable!T nullable
);
Parameters
Name | Description |
---|---|
range | the range to convert. It must have no more than 1 element |
nullable | the Nullable to convert |
Returns
an optional of the element of range or Nullable
Example
import std .algorithm: map;
import optional;
assert(no!int .map!"a" .toOptional == none);
assert(some(1) .map!"a" .toOptional == some(1));