Option

A struct which wraps a value and whether said value is "valid".

struct Option (

) {

this();

static Option!T some(T value);

static Option!T none();

bool hasValue [@property getter];

void reset();

T get();

T getOr(T value);

}

Constructors

this this(): Undocumented in source.

Alias This

hasValue

Members

Functions

get T get(): Gets the value stored within the Optional.
getOr T getOr(T value): Gets the value stored within the Optional if valid, otherwise returns the given value.
reset void reset(): Destroys the contained value.

Properties

hasValue bool hasValue [@property getter]: Whether this instance contains a valid value.

Static functions

none Option!T none(): Creates a new empty value.
some Option!T some(T value): Wraps value in an optional type.

Examples

Option!int positiveOnly(int value) @nogc nothrow {
    return value >= 0 ? some(value) : none!int();
}

auto rval = positiveOnly(4);
if (rval) {
    writeln("Value is positive!");
} else {
    writeln("Value is negative!");
}

Option

Constructors

Alias This

Members

Functions

Properties

Static functions

Examples

Meta

Source