https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88864
Bug ID: 88864
Summary: default template arguments not merged across all
declarations
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: barry.revzin at gmail dot com
Target Milestone: ---
Shorter repro from StackOverflow https://stackoverflow.com/q/54202462/2069064:
struct B {
template<typename T, typename U> B(T t);
};
template <typename T, typename U = int>
B::B(T t) { }
B b(3);
This is rejected by all versions of gcc because of an inability to deduce U.
