retype(), retype_return()

sigc::retype() alters a sigc::pointer_functor, a sigc::mem_functor or a sigc::slot in that it makes C-style casts to the functor's parameter types of all parameters passed through operator()(). More...

Classes
struct	sigc::retype_functor< T_functor, T_type >
	Adaptor that performs C-style casts on the parameters passed on to the functor. More...
struct	sigc::retype_return_functor< T_return, T_functor >
	Adaptor that performs a C-style cast on the return value of a functor. More...
struct	sigc::retype_return_functor< void, T_functor >
	Adaptor that performs a C-style cast on the return value of a functor. More...

Functions
template <template< typename T_func, typename... T_arg > class T_functor, typename T_func , typename... T_arg>
decltype(auto)	sigc::retype (const T_functor< T_func, T_arg... > &functor)
	Creates an adaptor of type sigc::retype_functor which performs C-style casts on the parameters passed on to the functor.
template <template< typename T_return, typename... T_arg > class T_functor, typename T_return , typename... T_arg>
decltype(auto)	sigc::retype (const T_functor< T_return(T_arg...)> &functor)
	Creates an adaptor of type sigc::retype_functor which performs C-style casts on the parameters passed on to the functor.
template <typename T_return , typename T_functor >
retype_return_functor< T_return, T_functor >	sigc::retype_return (const T_functor &functor)
	Creates an adaptor of type sigc::retype_return_functor which performs a C-style cast on the return value of the passed functor.

Detailed Description

sigc::retype() alters a sigc::pointer_functor, a sigc::mem_functor or a sigc::slot in that it makes C-style casts to the functor's parameter types of all parameters passed through operator()().

Use this adaptor for inline conversion between numeric or other simple types.

Example:

void foo(int);
sigc::retype(sigc::ptr_fun(&foo))(5.7F); // calls foo(5)

The functor that sigc::retype() returns can be passed directly into sigc::signal::connect() or sigc::signal::connect_first().

Example:

sigc::signal<void(float)> some_signal;
void foo(int);
some_signal.connect(sigc::retype(sigc::ptr_fun(&foo)));

This adaptor builds an exception in that it only works on sigc::pointer_functor, sigc::mem_functor and sigc::slot because it needs sophisticated information about the parameter types that cannot be deduced from arbitrary functor types.

sigc::retype_return() alters the return type of an arbitrary functor. Like in sigc::retype() a C-style cast is performed. Usage sigc::retype_return() is not restricted to libsigc++ functor types but you need to specify the new return type as a template parameter.

Example:

float foo();
std::cout << sigc::retype_return<int>(&foo)(); // converts foo's return value to an integer

Function Documentation

retype() [1/2]

template <template< typename T_func, typename... T_arg > class T_functor, typename T_func , typename... T_arg>

decltype(auto) sigc::retype ( const T_functor< T_func, T_arg... > &  functor )

inline

Creates an adaptor of type sigc::retype_functor which performs C-style casts on the parameters passed on to the functor.

Parameters

functor

Functor that should be wrapped.

Returns

Adaptor that executes functor performing C-style casts on the paramters passed on.

retype() [2/2]

template <template< typename T_return, typename... T_arg > class T_functor, typename T_return , typename... T_arg>

decltype(auto) sigc::retype ( const T_functor< T_return(T_arg...)> &  functor )

inline

Creates an adaptor of type sigc::retype_functor which performs C-style casts on the parameters passed on to the functor.

Parameters

functor

Functor that should be wrapped.

Returns

Adaptor that executes functor performing C-style casts on the paramters passed on.

retype_return()

template <typename T_return , typename T_functor >

retype_return_functor< T_return, T_functor > sigc::retype_return ( const T_functor &  functor )

inline

Creates an adaptor of type sigc::retype_return_functor which performs a C-style cast on the return value of the passed functor.

The template argument T_return specifies the target type of the cast.

Parameters

functor

Functor that should be wrapped.

Returns

Adaptor that executes functor performing a C-style cast on the return value.