Optional

Functions: operator==, print, println

enum Optional<T>

A value that may be absent.

None

None

Some

Some(T value),

print

void print(OutputStream& stream)

Writes the value, or null if there is none, to the given stream.

take

T? take()

Moves the optional out, leaving None in its place. Always call this on a pointer ((&opt).take()): a plain opt.take() unwraps and takes the payload instead, or fails to compile if the payload has no take() method.

operator==

bool operator== <T: Comparable>(T?& a, T?& b)

Returns true if both optionals are equal.

bool operator== <T: Comparable>(T?& a, T& b)

Returns true if the optional holds a value equal to b.

bool operator== <T: Comparable>(T& a, T?& b)

Returns true if the optional holds a value equal to a.

bool operator== <T: Comparable>(T&? a, T& b)

Returns true if the optional borrow is non-null and borrows a value equal to b.

bool operator== <T: Comparable>(T& a, T&? b)

Returns true if the optional borrow is non-null and borrows a value equal to a.

print

void print<T: Printable>(T?& optional)

Prints the given value.

void print<T: Printable>(T&? optional)

Prints the given optional borrow.

println

void println<T: Printable>(T&? optional)

Prints the given optional borrow followed by a newline.