| Issue |
157281
|
| Summary |
rejects valid on `if constexpr` with dependent access restrictions
|
| Labels |
c++,
rejects-valid
|
| Assignees |
|
| Reporter |
wheatman
|
I think the following code is valid but being rejected
```cpp
#include <type_traits>
class has_x {
protected:
int x();
};
class no_x {};
template <class A> class D : public A {
public:
int foo() {
if constexpr (std::is_base_of_v<has_x,D>) {
return has_x::x();
}
return 0;
}
};
int y() {
D<no_x> d;
return d.foo();
}
```
The error is
```
<source>:15:27: error: 'x' is a protected member of 'has_x'
15 | return has_x::x();
| ^
<source>:24:14: note: in instantiation of member function 'D<no_x>::foo' requested here
24 | return d.foo();
| ^
<source>:5:9: note: declared protected here
5 | int x();
| ^
1 error generated.
Compiler returned: 1
```
https://godbolt.org/z/G9v1qfWxj
I am not a standards expert, but we are inside a template entity so the statement should be discarded. I will note the switching which class is inside the template does allow the code to cpmpile showing we are not ill-formed for every possible specialization.
The code is accepted by gcc 15.2 and msvc 19.43
Tested with clang 21.1 and and current master (4d0b81616975c4ea8984170122a04553cb14337a)
![]()
_______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
