https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101402
Bug ID: 101402
Summary: top cv qualifier not dropped for array type typedef in
template class (core 1001)
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: ---
Created attachment 51127
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51127&action=edit
a diagnositic message to print functions arguments for comparison
This example code from core
1001(http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1001) is still
giving no matching template declaration error.
template<class T> struct A {
typedef T arr[3];
};
template<class T> void f(const typename A<T>::arr) { } // #1
template void f<int>(const A<int>::arr);
1. This happens for all gcc versions. The root cause is template function
argument is considered as ‘(const int*)’ instead of ‘(int*)’ (see attached
debug output for details.)
2. C++ standard requires top level cv qualifier being dropped when forming
function type.(https://timsong-cpp.github.io/cppwp/dcl.fct#5)
3. When both 'const' are removed from template function and specialization,
there is no error which proves array type works as long as there is no top
level cv qualifier.
4. I feel this is rather a high-profile bug as the example code is listed in
active core language issues long ago, particularly when both clang and MSVC
have fixed this issue. (see godbolt: https://www.godbolt.org/z/cofrEWEbs)
