https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90998
--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Author: mpolacek Date: Tue Oct 29 21:06:21 2019 New Revision: 277593 URL: https://gcc.gnu.org/viewcvs?rev=277593&root=gcc&view=rev Log: PR c++/90998 - ICE with copy elision in init by ctor and -Wconversion. After r269667 which introduced joust_maybe_elide_copy, in C++17 we can elide a constructor if it uses a conversion function that returns a prvalue, and use the conversion function in its stead. This eliding means that if we have a candidate that previously didn't have ->second_conv, it can have it after the elision. This confused the -Wconversion warning because it was assuming that if cand1->second_conv is non-null, so is cand2->second_conv. Here cand1->second_conv was non-null but cand2->second_conv remained null, so it crashed in compare_ics. I checked with clang that both compilers call A::operator B() in C++17 and B::B(A const &) otherwise. * call.c (joust): Don't attempt to warn if ->second_conv is null. * g++.dg/cpp0x/overload-conv-4.C: New test. Added: trunk/gcc/testsuite/g++.dg/cpp0x/overload-conv-4.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/call.c trunk/gcc/testsuite/ChangeLog
