[Bug c++/87530] New: copy elision in return statement doesn't check for rvalue reference to object type

[barry.revzin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87530

            Bug ID: 87530
           Summary: copy elision in return statement doesn't check for
                    rvalue reference to object type
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: barry.revzin at gmail dot com
  Target Milestone: ---

Example from StackOverflow (https://stackoverflow.com/q/52662407/2069064):

struct Base { };

template<typename T>
struct A : Base
{
    A();
    A(Base&&);
};

A<int> foo()
{
    A<double> v;
    return v;
}

gcc accepts this code, invoking the A(Base&&) constructor in the return
statement. But the requirement in [class.copy.elision]/3 requires the first
type in the selected constructor to be an rvalue reference to the object's
type, which it is not.