https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68190
--- Comment #3 from Daniel Krügler <daniel.kruegler at googlemail dot com> --- (In reply to Markus Trippelsdorf from comment #1) Markus, could you please elaborate on your reference to LWG 103? At the moment I see no relation to the code example. With acceptance of http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3657.htm support for heterogeneous comparison had been added. But this still requires as of Table 101 — Associative container requirements that a.find(k) and a_tran.find(ke) return the very same type set<>::iterator for a non-constant set object and the expression a.erase(q) also shall have type set<>::iterator return type. The only option, that LWG 103 allows is that for a given implementation set<>::iterator and set<>::const_iterator *could* be of the same type, but that is not the problem here. There is a different way to point out the problem here by replacing the last code line containing the erase expression iter = s.erase(iter); by the following two lines: auto iter2 = s.find(1); static_assert(std::is_same<decltype(iter), decltype(iter2)>::value, ""); This static assertion fails and just demonstrates that a.find(k) and a_tran.find(ke) do have different return types.
