compose()

sigc::compose() combines two or three arbitrary functors. More...

Classes
struct	sigc::compose1_functor< T_setter, T_getter >
	Adaptor that combines two functors. More...
struct	sigc::compose2_functor< T_setter, T_getter1, T_getter2 >
	Adaptor that combines three functors. More...

Functions
template <typename T_setter , typename T_getter >
compose1_functor< T_setter, T_getter >	sigc::compose (const T_setter &setter, const T_getter &getter)
	Creates an adaptor of type sigc::compose1_functor which combines two functors.
template <typename T_setter , typename T_getter1 , typename T_getter2 >
compose2_functor< T_setter, T_getter1, T_getter2 >	sigc::compose (const T_setter &setter, const T_getter1 &getter1, const T_getter2 &getter2)
	Creates an adaptor of type sigc::compose2_functor which combines three functors.

Detailed Description

sigc::compose() combines two or three arbitrary functors.

On invocation, parameters are passed on to one or two getter functor(s). The return value(s) are then passed on to the setter function.

Examples:

float square_root(float a)  { return sqrtf(a); }
float sum(float a, float b) { return a+b; }
std::cout << sigc::compose(&square_root, &sum)(9, 16); // calls square_root(sum(3,6))
std::cout << sigc::compose(&sum, &square_root, &square_root)(9); // calls sum(square_root(9),
square_root(9))

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

Example:

sigc::signal(float(float, float)> some_signal;
some_signal.connect(sigc::compose(&square_root, &sum));

Function Documentation

compose() [1/2]

template <typename T_setter , typename T_getter >

compose1_functor< T_setter, T_getter > sigc::compose ( const T_setter &  setter, const T_getter &  getter  )

inline

Creates an adaptor of type sigc::compose1_functor which combines two functors.

Parameters

setter	Functor that receives the return value of the invocation of getter.
getter	Functor to invoke from operator()().

Returns

Adaptor that executes setter with the value returned from invocation of getter.

compose() [2/2]

template <typename T_setter , typename T_getter1 , typename T_getter2 >

compose2_functor< T_setter, T_getter1, T_getter2 > sigc::compose ( const T_setter &  setter, const T_getter1 &  getter1, const T_getter2 &  getter2  )

inline

Creates an adaptor of type sigc::compose2_functor which combines three functors.

Parameters

setter	Functor that receives the return values of the invocation of getter1 and getter2.
getter1	Functor to invoke from operator()().
getter2	Functor to invoke from operator()().

Returns

Adaptor that executes setter with the values return from invocation of getter1 and getter2.