reinterpret_cast from const void* to function pointer does not compile #134867
Description
GCC and MSVC both allow a reinterpret_cast to convert from a const void* to void (*)(void*).
Clang refuses because we are "casting away qualifiers" (const), but there is no qualifier to add on the function-pointer side. There is no syntax for assigning values into a function pointer and there is no possible addition of const into the function pointer type which makes the cast allowed.
This can be worked around by using const_cast to strip the const off the void*, or by using a C-style cast, but this seems like it shouldn't be necessary, and no other mainstream compiler requires it.
Example: https://godbolt.org/z/7rxqss7nT
using FuncPtr = void (*)(void*);
extern "C" const void* Lookup(const void* OriginalFunction);
FuncPtr MakeVoidFuncPtr(const void* Func) {
return reinterpret_cast<FuncPtr>(Lookup(Func));
}