https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94326
Bug ID: 94326
Summary: g++: error: pack.ii: ‘-fcompare-debug’ failure
(length)
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: marxin at gcc dot gnu.org
CC: jakub at gcc dot gnu.org
Target Milestone: ---
This one is very old (at least GCC 4.8.0):
$ cat pack.ii
template <typename = int> class A {
const int &m_fn1() { return 0; }
public:
template <typename _Kt> void m_fn2(_Kt) { m_fn1(); }
};
class B {
A<> _M_t;
public:
template <typename _Kt> auto m_fn3(_Kt p1) -> decltype(_M_t.m_fn2(p1)) {
_M_t.m_fn2(p1);
}
};
struct C {};
void operator<(C, int) {
B a;
a.m_fn3(C{});
}
$ g++ pack.ii -c -fcompare-debug -std=c++11
pack.ii: In instantiation of ‘const int& A< <template-parameter-1-1> >::m_fn1()
[with <template-parameter-1-1> = int]’:
pack.ii:5:45: required from ‘void A< <template-parameter-1-1> >::m_fn2(_Kt)
[with _Kt = C; <template-parameter-1-1> = int]’
pack.ii:12:15: required from ‘decltype
(((B*)this)->B::_M_t.A<>::m_fn2<_Kt>(p1)) B::m_fn3(_Kt) [with _Kt = C; decltype
(((B*)this)->B::_M_t.A<>::m_fn2<_Kt>(p1)) = void]’
pack.ii:18:14: required from here
pack.ii:2:31: warning: returning reference to temporary [-Wreturn-local-addr]
2 | const int &m_fn1() { return 0; }
| ^
g++: error: pack.ii: ‘-fcompare-debug’ failure (length)
