fcppt::optional Namespace Reference

Classes
struct	is_object
	Checks if a given type is an fcppt::optional::object. More...
struct	is_object< fcppt::optional::object< Type > >
struct	nothing
	A polymorphic empty optional. More...
class	object
	A class that makes values optional. More...

Typedefs
template<fcppt::optional::object_concept Optional>
using	move_type = fcppt::move_if_rvalue_type< Optional, fcppt::optional::reference_type< Optional > >
	The moved inner type of an optional.
template<typename T >
using	reference = fcppt::optional::object< fcppt::reference< T > >
	Optional of a reference.
template<fcppt::optional::object_concept Optional>
using	reference_type = decltype(std::declval< Optional >().get_unsafe())
	The reference type of an optional.
template<fcppt::optional::object_concept Optional>
using	value_type = fcppt::type_traits::value_type< std::remove_cvref_t< Optional > >
	The value type of an optional.

Functions
template<fcppt::optional::object_concept Optional, fcppt::concepts::invocable_move<> Function> requires std::is_same_v<std::remove_cvref_t<Optional>, std::invoke_result_t<Function>>
std::remove_cvref_t< Optional >	alternative (Optional &&_optional1, Function const &_optional2)
	Returns the first optional if it is not nothing.
template<fcppt::optional::object_concept... Optionals, fcppt::concepts::invocable_move< fcppt::optional::move_type< Optionals >... > Function>
fcppt::optional::object< std::invoke_result_t< Function, fcppt::optional::move_type< Optionals >... > >	apply (Function const &_function, Optionals &&..._optionals)
	Applies a function to multiple optionals if each of them contains a value.
template<typename Element , typename Arg > requires std::is_same_v<Element, std::remove_cv_t<Arg>>
Element &	assign (fcppt::optional::object< Element > &_optional, Arg &&_arg)
	Assigns an optional and returns a reference to the optional's contents.
template<fcppt::optional::object_concept Optional, fcppt::concepts::invocable_move< fcppt::optional::move_type< Optional > > Function> requires fcppt::optional::is_object_v< std::invoke_result_t<Function, fcppt::optional::move_type<Optional>>>
std::invoke_result_t< Function, fcppt::optional::move_type< Optional > >	bind (Optional &&_source, Function const &_function)
	Converts an optional of one type to another.
template<typename TargetContainer , typename Source >
TargetContainer	cat (Source &&_source)
	Removes empty optionals from a range.
template<fcppt::optional::object_concept Optional1, fcppt::optional::object_concept Optional2, fcppt::concepts::invocable_move< fcppt::optional::move_type< Optional1 >, fcppt::optional::move_type< Optional2 > > Function> requires std:: is_same_v<fcppt::optional::value_type<Optional1>, fcppt::optional::value_type<Optional2>> && std::is_same_v< fcppt::optional::value_type<Optional1>, std::invoke_result_t< Function, fcppt::optional::move_type<Optional1>, fcppt::optional::move_type<Optional2>>>
fcppt::optional::object< fcppt::optional::value_type< Optional1 > >	combine (Optional1 &&_optional1, Optional2 &&_optional2, Function const &_function)
	Combines two optionals.
template<typename T >
bool	operator== (fcppt::optional::object< T > const &_a, fcppt::optional::object< T > const &_b)
	Compares two optionals for equality.
template<typename T >
bool	operator!= (fcppt::optional::object< T > const &_a, fcppt::optional::object< T > const &_b)
	Compares two optionals for inequality.
template<typename T >
bool	operator< (fcppt::optional::object< T > const &_a, fcppt::optional::object< T > const &_b)
	Compares two optionals lexicographically.
template<typename Type >
fcppt::optional::object< std::remove_cv_t< Type > >	copy_value (fcppt::optional::reference< Type > const &_opt)
	Copies the value of an optional reference.
template<typename Element >
fcppt::optional::object< fcppt::reference< std::remove_reference_t< decltype(*std::declval< Element >())> >	deref (fcppt::optional::object< Element > const &_optional)
	Dereferences the contents of an optional.
template<fcppt::optional::object_concept Optional, fcppt::concepts::invocable_move< fcppt::optional::value_type< Optional > > Function> requires std::is_same_v<bool, std::invoke_result_t<Function, fcppt::optional::value_type<Optional>>>
std::remove_cvref_t< Optional >	filter (Optional &&_source, Function const &_function)
	Filters an optional.
template<fcppt::optional::object_concept Optional, fcppt::concepts::invocable_move Default> requires std::is_same_v<std::invoke_result_t<Default>, fcppt::optional::value_type<Optional>>
std::invoke_result_t< Default >	from (Optional &&_optional, Default const _default)
	Returns the value contained in an optional or a default value.
template<typename T >
fcppt::optional::reference< T >	from_pointer (T *const _pointer)
	Creates an optional reference from a pointer.
template<typename Element , fcppt::concepts::invocable_move<> Function> requires std::is_same_v<std::invoke_result_t<Function>, Element>
Element &	get_or_assign (fcppt::optional::object< Element > &_optional, Function const &_function)
	Assigns an optional if it is empty. Returns a reference to the optional's contents.
template<fcppt::optional::object_concept Optional> requires fcppt::optional::is_object_v<fcppt::optional::value_type<Optional>>
fcppt::optional::value_type< Optional >	join (Optional &&_source)
	Removes one layer of optionals.
template<typename Type >
fcppt::optional::object< std::remove_cvref_t< Type > >	make (Type &&_value)
	Wraps a value into an optional.
template<fcppt::concepts::invocable_move Function>
fcppt::optional::object< std::invoke_result_t< Function > >	make_if (bool const _is_set, Function const &_function)
	Creates an optional depending on a boolean.
template<fcppt::optional::object_concept Optional, fcppt::concepts::invocable_move< fcppt::optional::move_type< Optional > > Function>
fcppt::optional::object< std::invoke_result_t< Function, fcppt::optional::move_type< Optional > > >	map (Optional &&_source, Function const &_function)
	Maps over an optional using a function.
template<fcppt::optional::object_concept Optional, fcppt::concepts::invocable Default, fcppt::concepts::invocable< fcppt::optional::move_type< Optional > > Transform> requires std::is_same_v< std::invoke_result_t<Default>, std::invoke_result_t<Transform, fcppt::optional::move_type<Optional>>>
std::invoke_result_t< Default >	maybe (Optional &&_optional, Default const &_default, Transform const &_transform)
	Transforms an optional value or returns a default value.
template<fcppt::optional::object_concept... Optionals, fcppt::concepts::invocable Default, fcppt::concepts::invocable< fcppt::optional::move_type< Optionals >... > Transform> requires std::is_same_v< std::invoke_result_t<Default>, std::invoke_result_t<Transform, fcppt::optional::move_type<Optionals>...>>
std::invoke_result_t< Default >	maybe_multi (Default const _default, Transform const _transform, Optionals &&..._optionals)
	Transforms multiple optional values or returns a default value.
template<fcppt::optional::object_concept Optional, fcppt::concepts::invocable< fcppt::optional::move_type< Optional > > Transform>
void	maybe_void (Optional &&_optional, Transform const &_transform)
	Transforms an optional value or does nothing.
template<fcppt::optional::object_concept... Optionals, fcppt::concepts::invocable< fcppt::optional::move_type< Optionals >... > Transform>
void	maybe_void_multi (Transform const _transform, Optionals &&..._optionals)
	Transforms optional values or does nothing.
template<typename Type , typename Ch , typename Traits >
std::basic_ostream< Ch, Traits > &	operator<< (std::basic_ostream< Ch, Traits > &_stream, fcppt::optional::object< Type > const &_opt_value)
	Outputs an optional to a basic_ostream.
template<typename ResultContainer , typename Source >
fcppt::optional::object< ResultContainer >	sequence (Source &&_source)
	Turns a container of optionals into an optional container.
template<typename Container , fcppt::optional::object_concept Optional> requires std::is_same_v<fcppt::type_traits::value_type<Container>, fcppt::optional::value_type<Optional>>
Container	to_container (Optional &&_source)
	Puts the value of an optional into a container or returns an empty container.
template<fcppt::optional::object_concept Optional, fcppt::concepts::invocable_move MakeException>
fcppt::optional::move_type< Optional >	to_exception (Optional &&_optional, MakeException const _make_exception)
	Returns the value contained in an optional or throws an exception.
template<typename T >
T *	to_pointer (fcppt::optional::reference< T > const _optional)
	Converts an optional reference to a pointer.

Variables
template<typename T >
constexpr bool	is_object_v = fcppt::optional::is_object<T>::value
	Checks if a given type is an fcppt::optional::object.