[Bug c++/78209] New: rvalue reference binding to an lvalue accepted

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78209

            Bug ID: 78209
           Summary: rvalue reference binding to an lvalue accepted
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: accepts-invalid
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
                CC: jason at gcc dot gnu.org
  Target Milestone: ---

This came up on the isocpp mailing list yesterday:

markus@x4 /tmp % cat test.ii
int main() {
  int &&i = 0;
  decltype(auto) j = i;
  return j;
}

markus@x4 /tmp % clang++ test.ii
test.ii:3:18: error: rvalue reference to type 'int' cannot bind to lvalue of
type 'int'
  decltype(auto) j = i;
                 ^   ~
1 error generated.

markus@x4 /tmp % icpc test.ii
test.ii(3): error: an rvalue reference cannot be bound to an lvalue
    decltype(auto) j = i;
                       ^
compilation aborted for test.ii (code 2)

markus@x4 /tmp % g++ -Wall -Wextra test.ii
markus@x4 /tmp %