libsigc++ 2.12.0
Public Types | Static Public Member Functions | List of all members
sigc::deduce_result_type< T_functor, T_args > Struct Template Reference

Deduce the return type of a functor. More...

#include <sigc++/adaptors/deduce_result_type.h>

Public Types

using type = decltype(test< T_functor >())
 

Static Public Member Functions

template<class U_functor , typename = typename std::is_base_of<adaptor_base, T_functor>::type>
static U_functor::template deduce_result_type< T_args... >::type test ()
 
template<class U_functor >
static functor_trait< T_functor >::result_type test ()
 

Detailed Description

template<class T_functor, class... T_args>
struct sigc::deduce_result_type< T_functor, T_args >

Deduce the return type of a functor.

typename deduce_result_type<functor_type, list of arg_types>::type deduces a functor's result type if functor_type inherits from sigc::functor_base and defines result_type or if functor_type is actually a (member) function type. Multi-type functors are not supported.

sigc++ adaptors use typename deduce_result_type<functor_type, list of arg_types>::type to determine the return type of their templated operator() overloads.

Adaptors in turn define a nested template class deduce_result_type that is used by template specializations of the global deduce_result_type template to correctly deduce the return types of the adaptor's suitable template operator() overload.

Member Typedef Documentation

◆ type

template <class T_functor , class... T_args>
using sigc::deduce_result_type< T_functor, T_args >::type = decltype (test<T_functor> ())

Member Function Documentation

◆ test() [1/2]

template <class T_functor , class... T_args>
template <class U_functor , typename = typename std::is_base_of<adaptor_base, T_functor>::type>
static U_functor::template deduce_result_type< T_args... >::type sigc::deduce_result_type< T_functor, T_args >::test ( )
static

◆ test() [2/2]

template <class T_functor , class... T_args>
template <class U_functor >
static functor_trait< T_functor >::result_type sigc::deduce_result_type< T_functor, T_args >::test ( )
static