https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87904
Bug ID: 87904 Summary: [9 Regression] ICE in lookup_mark, at cp/tree.c:2322 since r265679 Product: gcc Version: 9.0 Status: UNCONFIRMED Keywords: ice-on-valid-code Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: marxin at gcc dot gnu.org CC: nathan at gcc dot gnu.org Target Milestone: --- Reduced test-case: $ cat filer.ii struct a {}; namespace { void operator<<(a, int) {}; } struct b { friend a &operator<<(a &, const b &); }; using ::operator<<; void operator<<(a, b); a &operator<<(a &c, const b &) { c << 123; }