https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104305
Bug ID: 104305
Summary: Partial specialization with parameter pack is ignored
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: fchelnokov at gmail dot com
Target Milestone: ---
This program:
```
#include <type_traits>
template<template<typename...> class TT, typename T1>
class A {};
template<typename T>
struct is_a : std::false_type {};
template<template<typename...> class TT, typename... T>
struct is_a<A<TT, T...>> : std::true_type {};
template<typename... T>
struct TT {};
int main() {
static_assert( is_a<A<TT, int>>::value );
}
```
is accepted in Clang and MSVC, but not in GCC, where static_assert is violated.
Demo: https://gcc.godbolt.org/z/d5s9hzaca
Related discussion: https://stackoverflow.com/q/52129797/7325599
