https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89831
Bug ID: 89831
Summary: passing 'const ...' as 'this' argument discards
qualifiers
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: lumosimann at gmail dot com
Target Milestone: ---
Starting from GCC 8.1, the following code does not compile anymore:
```
struct Q {
int operator[](int i) { return 0; }
int operator[](int i) const { return 0; }
};
struct Base {
Q x;
};
struct X : public Base {
template <typename T>
void f(T) const {
auto q = Base::x[0];
}
};
int main() { X{}.f(3); }
```
https://godbolt.org/z/UefNCx
- using `operator()` instead of `operator[]` fixes the problem
- using `x[0]` instead of `Base::x[0]` fixes the problem
- removing the template from `X::f` fixes the problem
In older versions and with clang, compilation is okay.
