https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96647
Bug ID: 96647
Summary: Can't resolve pointer to overloaded member with auto
return type
Product: gcc
Version: 10.2.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: rustamabd at gmail dot com
Target Milestone: ---
auto return type in combination with overloading and CRTP results in an
overload set that cannot be disambiguated.
Example:
template<typename T>
struct Base {
auto f(int) { return static_cast<T*>(this); }
auto f(char) { return static_cast<T*>(this); }
};
struct A : Base<A> {};
int main() {
A instance;
// instance.f('x') // "fixes" the issue
auto ptr = static_cast<A* (A::*)(char)>(&A::f); // error here
(instance.*ptr)('x');
}
Error:
error: no matches converting function 'f' to type 'struct A* (struct
A::*)(char)'
14 | auto ptr = static_cast<A* (A::*)(char)>(&A::f); // error here
| ^
note: candidates are: 'auto Base<T>::f(char) [with T = A]'
4 | auto f(char) { return static_cast<T*>(this); }
| ^
note: 'auto Base<T>::f(int) [with T = A]'
3 | auto f(int) { return static_cast<T*>(this); }
| ^
Replacing "auto" with "T*", as well as invoking instance.f('x'), fixes the
issue.
clang compiles the code fine.
