https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120015
Bug ID: 120015
Summary: internal compiler error: in unify, at cp/pt.cc:25969
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ldalessandro at gmail dot com
Target Milestone: ---
Invalid code uses tag<T> without a second parameter.
template <class T, auto = []{}>
struct tag {};
template <class T>
bool foo(tag<T>);
tag<int> x;
auto y = foo(x);
Works for valid code:
template <class T, auto v>
bool foo(tag<T, v>);
Live: https://godbolt.org/z/YKorqs95P [April 29th, 2025]
