std:: swap (std::function)

Overloads the std::swap algorithm for std::function . Exchanges the state of lhs with that of rhs . Effectively calls lhs. swap ( rhs ) .

Parameters

Return value

(none)

Example

#include <functional>
#include <iostream>
 
void foo(const char* str, int x)
{
    std::cout << "foo(\"" << str << "\", " << x << ")\n";
}
 
void bar(const char* str, int x)
{
    std::cout << "bar(\"" << str << "\", " << x << ")\n";
}
 
int main()
{
    std::function<void(const char*, int)> f1{foo};
    std::function<void(const char*, int)> f2{bar};
 
    f1("f1", 1);
    f2("f2", 2);
 
    std::cout << "std::swap(f1, f2);\n";
    std::swap(f1, f2);
 
    f1("f1", 1);
    f2("f2", 2);
}

foo("f1", 1)
bar("f2", 2)
std::swap(f1, f2);
bar("f1", 1)
foo("f2", 2)

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also