https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97572
Bug ID: 97572
Summary: [c++ 20] Constraining is broken
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: dimitri.gorokhovik at free dot fr
Target Milestone: ---
The code:
constexpr bool any (bool) { return true; };
template <typename T> concept Any = requires (T t) { requires any (t); };
constexpr static int f (Any auto) { return 42; };
constexpr auto q = f (false);
when compiled as:
g++ -std=c++20 -o bug-9.o -c bug-9.cpp
produces:
bug-9.cpp: In substitution of ‘template<class auto:1> requires Any<auto:1>
constexpr int f(auto:1) [with auto:1 = bool]’:
bug-9.cpp:5:28: required from here
bug-9.cpp:3:63: error: ‘t’ is not a constant expression
3 | template <typename T> concept Any = requires (T t) { requires any (t);
};
| ~~~~~~~~~^~~~~~~
bug-9.cpp:5:28: error: no matching function for call to ‘f(bool)’
5 | constexpr auto q = f (false);
| ^
bug-9.cpp:4:22: note: candidate: ‘template<class auto:1> requires Any<auto:1>
constexpr int f(auto:1)’
4 | constexpr static int f (Any auto) { return 42; };
| ^
bug-9.cpp:4:22: note: substitution of deduced template arguments resulted in
errors seen above
GCC version:
g++ (GCC) 11.0.0 20201025 (experimental)
