std::addressof

 

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Defined in header <memory>
	(1)
template< class T > T* addressof(T& arg);			(since C++11) (until C++17)
template< class T > constexpr T* addressof(T& arg);			(since C++17)
template <class T> const T* addressof(const T&&) = delete;		(2)	(since C++17)

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

2) Rvalue overload is deleted to prevent taking the address of const rvalues.

The expression std::addressof(E) is a constant subexpression, if E is an lvalue constant subexpression.

(since C++17)

Parameters

arg

-

lvalue object or function

Return value

Pointer to arg.

Exceptions

1)

noexcept specification:  

noexcept

  

Possible implementation

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

Note: the above implementation is oversimplified and is not constexpr (which requires compiler support).