https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50462
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Oh, it's the overloaded function thjat makes the difference between saying
"invalid use of non-static member function" and trying to do overload
resolution with an <unresolved overloaded function type>.
Reduced example that actually reproduces the original problem:
struct ostream { };
void operator<<(ostream, int) { }
void operator<<(ostream, void*) { }
void operator<<(ostream, char*) { }
struct V
{
int size() { return 0; };
int size() const { return 0; };
};
void print(V v)
{ ostream() << v.size; }
Which prints this with current trunk:
50462.C: In function 'void print(V)':
50462.C:14:13: error: no match for 'operator<<' (operand types are 'ostream'
and '<unresolved overloaded function type>')
14 | { ostream() << v.size; }
| ~~~~~~~~~ ^~ ~~~~~~
| | |
| ostream <unresolved overloaded function type>
50462.C:3:6: note: candidate: 'void operator<<(ostream, int)'
3 | void operator<<(ostream, int) { }
| ^~~~~~~~
50462.C:3:26: note: no known conversion for argument 2 from '<unresolved
overloaded function type>' to 'int'
3 | void operator<<(ostream, int) { }
| ^~~
50462.C:4:6: note: candidate: 'void operator<<(ostream, void*)'
4 | void operator<<(ostream, void*) { }
| ^~~~~~~~
50462.C:4:26: note: no known conversion for argument 2 from '<unresolved
overloaded function type>' to 'void*'
4 | void operator<<(ostream, void*) { }
| ^~~~~
50462.C:5:6: note: candidate: 'void operator<<(ostream, char*)'
5 | void operator<<(ostream, char*) { }
| ^~~~~~~~
50462.C:5:26: note: no known conversion for argument 2 from '<unresolved
overloaded function type>' to 'char*'
5 | void operator<<(ostream, char*) { }
| ^~~~~
I don't see why we should treat v.size any differently whether it's overloaded
or not. It's invalid either way, so we should fail similarly.
