https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95175
Bug ID: 95175
Summary: constexpr and alias template
Product: gcc
Version: 9.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: nina.didenko at gmail dot com
Target Milestone: ---
This snippet successfully compiles using gcc6 up to gcc8.
When building using gcc 9.3.0 there is an error
template<typename R, typename... Types>
using Function = R(*)(Types...);
struct Struct
{
void *addr;
template<typename R, typename... Types>
constexpr Struct(Function<R, Types...> addr) : addr((void*)(addr)) {}
};
void TestFunction()
{
}
int main(void)
{
static constexpr Struct functions[]{
{TestFunction},
};
}
The error is
4.cpp: In function 'int main()':
4.cpp:20:3: error: 'constexpr Struct::Struct(Function<R, Types ...>) [with R =
void; Types = {}; Function<R, Types ...> = void (*)()]' called in a constant
expression
20 | };
| ^
4.cpp:9:13: note: 'constexpr Struct::Struct(Function<R, Types ...>) [with R =
void; Types = {}; Function<R, Types ...> = void (*)()]' is not usable as a
'constexpr' function because:
9 | constexpr Struct(Function<R, Types...> addr) : addr((void*)(addr)) {}
The full product code
https://github.com/TES3MP/openmw-tes3mp/blob/0.7.1/apps/openmw-mp/Script/ScriptFunctions.hpp#L120
https://github.com/TES3MP/openmw-tes3mp/blob/0.7.1/apps/openmw-mp/Script/Types.hpp#L99
