function::operator=

Článek
06/09/2015

Nahradí uložené callable objektu.

function& operator=(null_ptr_type npc);
function& operator=(const function& right);
template<class Fty>
    function& operator=(Fty fn);
template<class Fty>
    function& operator=(reference_wrapper<Fty> fnref);

Parametry

npc
Konstanta ukazatele null.
right
Objekt funkce kopírování.
fn
Callable objektu obtékat.
fnref
Odkaz na objekt callable obtékání textu.

Poznámky

Provozovatelé jednotlivých nahradit callable objekt držení *this s callable objekt předán jako operand.

Příklad

// std_tr1__functional__function_operator_as.cpp 
// compile with: /EHsc 
#include <functional> 
#include <iostream> 
 
int neg(int val) 
    { 
    return (-val); 
    } 
 
int main() 
    { 
    std::function<int (int)> fn0(neg); 
    std::cout << std::boolalpha << "empty == " << !fn0 << std::endl; 
    std::cout << "val == " << fn0(3) << std::endl; 
 
    std::function<int (int)> fn1; 
    fn1 = 0; 
    std::cout << std::boolalpha << "empty == " << !fn1 << std::endl; 
 
    fn1 = neg; 
    std::cout << std::boolalpha << "empty == " << !fn1 << std::endl; 
    std::cout << "val == " << fn1(3) << std::endl; 
 
    fn1 = fn0; 
    std::cout << std::boolalpha << "empty == " << !fn1 << std::endl; 
    std::cout << "val == " << fn1(3) << std::endl; 
 
    fn1 = std::cref(fn1); 
    std::cout << std::boolalpha << "empty == " << !fn1 << std::endl; 
    std::cout << "val == " << fn1(3) << std::endl; 
 
    return (0); 
    }