toOptional

Converts a range or Nullable to an optional type

auto toOptional(R range)
auto
toOptional
(
R
)
(
auto ref R range
)
if (
from.std.range.isInputRange!R
)
auto toOptional(Nullable!T nullable)

Parameters

range R: the range to convert. It must have no more than 1 element

Return Value

Type: auto

an optional of the element of range or Nullable

Examples

import std.algorithm: map;
import optional;

assert(no!int.map!"a".toOptional == none);
assert(some(1).map!"a".toOptional == some(1));

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