This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 116a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-12-19

945. Use of this in a late-specified return type

(Moved from issue 760.)

Although it was considered and rejected as part of issue 643, more recent developments may argue in favor of allowing the use of this in a late-specified return type. In particular, declaring the return type for a forwarding function in a derived class template that invokes a member function of a dependent base class is difficult without this facility. For example:

    template <typename T> struct derived: base<T> {
      auto invoke() -> decltype(this->base_func()) {
        return this->base_func();
      }
    };

(See also issue 1207 for another potential motivation for a change to this rule.)

Additional note (October, 2010):

The question should also be considered for parameter types; for example,

class comparable {
public:
   bool is_equal(decltype(*this) other) { // should be X&
       return /*...*/;
   }
};

Proposed resolution (March, 2011):

This issue is resolved by the resolution of issues 1017 and 1207 in document N3282.