cal::optional< T > Class Template Reference

Represents an optional value. More...

#include <optional.hpp>

Public Member Functions
	optional ()
	Creates a disengaged optional value.
	optional (nullopt_t)
	Creates a disengaged optional value.
	optional (const T &value)
	Creates an engaged optional value.
	operator bool () const
	Returns whether the optional is engaged.
optional &	operator= (nullopt_t)
	Disengages the value from the optional.
template<class U >
optional &	operator= (const U &value)
	Assigns a value to the optional.
const T &	value () const
	Extracts the value from the optional. If there is none, an std::logic_error is thrown.
T &	value ()
	Extracts the value from the optional. If there is none, an std::logic_error is thrown.
template<class U >
T	value_or (const U &value) const
	Returns the value of the optional if it exists, or the given value argument otherwise.

Detailed Description

template<class T>
class cal::optional< T >

Represents an optional value.