https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96124
Bug ID: 96124
Summary: Template specialization auto
Product: gcc
Version: 10.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: amal029 at outlook dot com
Target Milestone: ---
#include <iostream>
template <auto N, auto M>
struct Add {
const static auto res = Add<N + 1, M - 1>::res;
};
template <auto N>
struct Add<N, 0> { const static auto res = N; };
/* This does not work, the second template argument overflows in Add struct */
/* Clang handles both cases correctly. */
template <std::size_t N>
//template <auto N> /* This works uncomment this line and comment the above
line to make it work */
auto Forall() { return Forall<N - 1>() + Add<N, N - 1>::res; }
template <>
auto Forall<0>() { return 0; }
int main(void) {
std::cout << Forall<3>() << "\n";
return 0;
}
See the comments in the code. I ran it on compiler explorer with both g++ 10.1
and gcc-trunk (x86-64); both fail. I should be able to narrow types myself.
Options when compiling -std=c++2a
