docwire::invocation_traits Namespace Reference

Provides traits classes for working with callable objects. More...

Classes
struct	args
	Extracts the argument types of a callable object. More...
struct	result
	Extracts the result type of a callable object. More...
struct	is_invocable
	Trait that checks if a type is invocable. More...

Typedefs
template<typename T >
using	args_t = typename args< T >::type
	Type alias for the type member of the args struct. More...
template<typename T >
using	result_t = typename result< T >::type
	Type alias for the type member of the result struct. More...

Variables
template<typename T >
constexpr std::size_t	arity_v = std::tuple_size_v<args_t<T>>
template<typename T >
constexpr bool	is_invocable_v = is_invocable<T>::value
	Variable template alias for the value of the is_invocable trait. More...

Detailed Description

Provides traits classes for working with callable objects.

This namespace contains traits classes that can be used to extract information about callable objects, such as their argument types and return types. It also provides a way to check if a type is invocable.

Typedef Documentation

args_t

template<typename T >

using docwire::invocation_traits::args_t = typedef typename args<T>::type

Type alias for the type member of the args struct.

The args struct is a meta-programming utility providing a convenient way to access the argument types of a callable object, with a fallback mechanism for cases where boost::callable_traits is not sufficient.

This type alias provides a shortcut for accessing the type member of the args struct.

Template Parameters

T	The type parameter for the args struct, typically a function type.

See also

args

Definition at line 91 of file invocation_traits.h.

result_t

template<typename T >

using docwire::invocation_traits::result_t = typedef typename result<T>::type

Type alias for the type member of the result struct.

The result struct is a meta-programming utility providing a convenient way to access the result type of a callable object, with a fallback mechanism for cases where boost::callable_traits is not sufficient.

This type alias provides a shortcut for accessing the type member of the result struct.

Template Parameters

T	The type parameter for the result struct, typically a function type.

See also

result

Definition at line 158 of file invocation_traits.h.

Variable Documentation

is_invocable_v

template<typename T >

constexpr bool docwire::invocation_traits::is_invocable_v = is_invocable<T>::value

inlineconstexpr

Variable template alias for the value of the is_invocable trait.

This variable template provides a convenient way to access the value of the is_invocable trait as a constant expression. It is equivalent to the nested value is_invocable<T>::value, but is often more readable and easier to use.

The is_invocable trait checks if a type is invocable, meaning it can be called like a function. Unlike std::is_invocable, this trait does not require specifying the argument types, making it easier to use with types that have complex or variable invocation signatures.

Additionally, this trait supports functors with overloaded operator() and other types that provide a public operator() signature through mechanisms such as invocation_args_t. This makes it a more comprehensive and robust solution for checking invocability.

The trait uses boost::callable_traits to check for invocability, and provides a fallback mechanism in cases where boost::callable_traits is not sufficient. The fallback mechanism relies on the presence of a public invocation_args_t type definition in the functor class.

Template Parameters

T	The type to check for invocability.

Definition at line 211 of file invocation_traits.h.