Optional

None alias None = .None: Undocumented in source.
Some alias Some = .Some!T: Undocumented in source.
back alias back = front: Undocumented in source.
empty alias empty = isNone: Undocumented in source.
length alias length = isSome: Undocumented in source.
opDollar alias opDollar(size_t dim : 0) = length: Undocumented in source.
popBack alias popBack = popFront: Undocumented in source.

Functions

front inout(T) front(): Undocumented in source. Be warned that the author may not have intended to support it.
isNone bool isNone(): Undocumented in source. Be warned that the author may not have intended to support it.
isSome bool isSome(): Undocumented in source. Be warned that the author may not have intended to support it.
opAssign auto ref opAssign(U rhs): Undocumented in source. Be warned that the author may not have intended to support it.
opAssign auto ref opAssign(None ): Undocumented in source. Be warned that the author may not have intended to support it.
opEquals bool opEquals(Optional rhs): Undocumented in source. Be warned that the author may not have intended to support it.
opEquals bool opEquals(None _): Undocumented in source. Be warned that the author may not have intended to support it.
opEquals bool opEquals(U rhs): Undocumented in source. Be warned that the author may not have intended to support it.
opIndex ref opIndex(): Undocumented in source. Be warned that the author may not have intended to support it.
opIndex inout(T) opIndex(size_t index): Undocumented in source. Be warned that the author may not have intended to support it.
opIndex ref opIndex(size_t[2] dim): Undocumented in source. Be warned that the author may not have intended to support it.
opSlice size_t[2] opSlice(size_t start, size_t end): Undocumented in source. Be warned that the author may not have intended to support it.
popFront void popFront(): Undocumented in source. Be warned that the author may not have intended to support it.
save inout(Optional) save(): Undocumented in source. Be warned that the author may not have intended to support it.

Static functions

none none(): Undocumented in source. Be warned that the author may not have intended to support it.
some some(U s): Undocumented in source. Be warned that the author may not have intended to support it.
some some(None ): Undocumented in source. Be warned that the author may not have intended to support it.

Variables

st SumType!(Some, None) st;: Undocumented in source.

Examples

alias O = Optional!int;

assert(O.some(3) == Some!int(3));
assert(O.none() == None());

assert(O.some(3).match!(
	(None _) => false, // use Some/None to match
	(int) => true,   // or use the underlying type to match
));

assert(O.init == O.init);
assert(O.some(0) != O.none());

static assert(!__traits(compiles, O.init = Some!(Some!int).init));
static assert(!__traits(compiles, Optional!O.init = Some!int.init));
static assert(!__traits(compiles, O.init = Some!short.init)); // TODO: should this be allowed?

static assert(!__traits(compiles, O.some(none)));
static assert( __traits(compiles, Optional!O.some(none)));
static assert( __traits(compiles, Optional!(Optional!O).some(none.some)));
static assert( __traits(compiles, Optional!(Optional!O).some(10.some.some)));
static assert(!__traits(compiles, Optional!(Optional!O).some(10.some.some.some)));
static assert(!__traits(compiles, Optional!(Optional!O).some(10.some)));

() @trusted
{
	assert((O.some(3) = 10.some) == 10.some);
	assert((O.some(3) = none) == none);
}
();

Optional

Alias This

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Functions

Static functions

Variables

Examples

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