https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102283
Bug ID: 102283
Summary: Inconsistent/wrong overload resolution when using an
initializer list and a defaulted template parameter
Product: gcc
Version: 11.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: dangelog at gmail dot com
Target Milestone: ---
Hello,
The following testcase has an "inconsistent" overload resolution:
template <typename U>
struct helper {};
struct data {};
template <typename T, typename E>
struct S
{
template <typename T2=T>
void f(T2 &&); // #1
template <typename E2=E>
void f(const helper<E2> &); // #2
};
int main() {
S<int, int> s1;
S<data, int> s2;
s1.f({});
s2.f({});
}
https://gcc.godbolt.org/z/nsj48M7af
On GCC 11, the the first call to f() resolves to #1, but the second call
resolves to #2. I cannot find any reason for this inconsistency in the ranking
of the overloads; no warnings are emitted under -Wall -Wextra.
Clang and MSVC both always call #1.
