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2598. addressof works on temporaries

Section: 20.2.11 [specialized.addressof] Status: C++17 Submitter: Brent Friedman Opened: 2016-03-06 Last modified: 2017-07-30

Priority: 3

View all other issues in [specialized.addressof].

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Discussion:

LWG issue 970(i) removed the rvalue reference overload for addressof. This allows const prvalues to bind to a call to addressof, which is dissimilar from the behavior of operator&. 

const vector<int> a();

void b()
{
  auto x = addressof(a()); // "ok"
  auto y = addressof<const int>(0); // "ok"
  auto z = &a(); //error: cannot take address of a temporary
}

[2016-08 Chicago]

Tues PM: Move to Tentatively Ready

Proposed resolution:

This wording is relative to N4582.

  1. Change 20.2.2 [memory.syn], header <memory> synopsis, as indicated:

    […]
// 20.9.12, specialized algorithms:
template <class T> constexpr T* addressof(T& r) noexcept;
template <class T> const T* addressof(const T&& elem) = delete;
[…]

  2. Change 20.2.11 [specialized.addressof] p1 as indicated:

    template <class T> constexpr T* addressof(T& r) noexcept;
template <class T> const T* addressof(const T&& elem) = delete;

    -1- Returns: The actual address of the object or function referenced by r, even in the presence of an overloaded operator&.