std::addressof - cppreference.com

De cppreference.com

Definido no cabeçalho `<memory>`

`template< class T > T* addressof(T& arg);`		(desde C++11)

Obtains the actual address of the object or function arg, even in presence of overloaded operator&

Parâmetros

arg

lvalue object or function

Valor de retorno

Pointer to arg.

Exceções

Possível implementação

template< class T >
T* addressof(T& arg) {
    return (T*)&(char&)arg;
}

Exemplo

operator& may be overloaded for a pointer wrapper class to obtain a pointer to pointer:

#include <iostream>
#include <memory>

template<class T>
struct Ptr {
   T* data;
   Ptr(T* arg) : data(arg) {}
   ~Ptr() {delete data;}
   T** operator&() { return &data; }
};

template<class T>
void f(Ptr<T>* p) {
    std::cout << "Ptr overload called with p = " << p << '\n';
}

void f(int** p) {
    std::cout << "int** overload called with p = " << p << '\n';
}

int main()
{
    Ptr<int> p(new int(42));
    f(&p);                 // calls int** overload
    f(std::addressof(p));  // calls Ptr<int>* overload
}

Saída:

int** overload called with p = 0012FF64
Ptr overload called with p = 0012FF64

Veja também


	the default allocator (modelo de classe) [edit]

	fornece informações sobre como os tipos de ponteiro Original: provides information about pointer-like types The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de classe) [edit]