https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102044
Bug ID: 102044
Summary: another case of template function signature
incorrectly dropping top-level cv-qualifier with
function parameter of array of template function
pointer
Product: gcc
Version: 10.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: nickhuang99 at hotmail dot com
Target Milestone: ---
This may be dup case of PR102033, PR102034 and very probably not related with
PR102042 of which I just changed the function parameter of "g" to const array
instead of const reference of array. So, it can be another test case.
However, clang(https://www.godbolt.org/z/fxzoWK4G8) passes,
MSVC++(https://www.godbolt.org/z/c7Pfbr6b9) fails like GCC. In this sense, I
believe this case might be different from all above cases because MSVC++ does
not fail.
consider:
#include<type_traits>
template<unsigned int N, class T>
void f(const T[N]){}
template<unsigned int N, class T>
using fPtr=decltype(f<N,T>)*;
template<unsigned int N, class T>
fPtr<N,T> af[N]={&f<N,T>};
template<unsigned int N, class T>
void g(const decltype(af<N,T>)){}
static_assert(std::is_same<decltype(af<1,int>),
fPtr<1,int>[1] >::value, "af is correct"); // #1
static_assert(std::is_same<decltype(g<1,int>),
void(const fPtr<1,int>[1])>::value, "fun"); // #2
template<>
void g<1,int>(const fPtr<1,int>[1]){}
GCC says:
error: template-id 'g<1, int>' for 'void g(void (* const*)(const int*))' does
not match any template declaration
21 | void g<1,int>(const fPtr<1,int>[1]){}
| ^~~~~~~~
fun-array-value.cpp:12:6: note: candidate is: 'template<unsigned int N, class
T> void g(decltype (af<N, T>))'
12 | void g(const decltype(af<N,T>)){}
| ^
