std::addressof
From cppreference.com
Defined in header
<memory>
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template< class T >
T* addressof(T& arg); |
(since C++11) | |
Obtains the actual address of the object or function arg
, even in presence of overloaded operator&
Contents |
[edit] Parameters
arg | - | lvalue object or function |
[edit] Return value
Pointer to arg
.
[edit] Exceptions
[edit] Possible implementation
template< class T > T* addressof(T& arg) { return reinterpret_cast<T*>( &const_cast<char&>( reinterpret_cast<const volatile char&>(arg))); } |
[edit] Example
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 }
Output:
int** overload called with p = 0012FF64 Ptr overload called with p = 0012FF64
[edit] See also
the default allocator (class template) |
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(C++11)
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provides information about pointer-like types (class template) |