https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90642
Bug ID: 90642
Summary: g++ fails to resolve template function overload
Product: gcc
Version: 4.8.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: oknenavin at outlook dot com
Target Milestone: ---
the following code fails to compile:
template <typename X = int, typename T, typename ...R>
inline void func(const T&, R...) {}
template <typename T>
struct S {};
template <typename X = int, typename T, typename ...R>
inline void func(const S<T>&, R...) {}
int main() {
func(42);
func(S<int>()); // OK
func(S<int>(), 1); // NOK
func<int>(S<int>(), 1); // NOK
}
with:
<source>: In function 'int main()':
<source>:13:21: error: call of overloaded 'func(S<int>, int)' is ambiguous
func(S<int>(), 1); // NOK
^
<source>:13:21: note: candidates are:
<source>:2:17: note: void func(const T&, R ...) [with X = int; T = S<int>;
R = {int}]
inline void func(const T&, R...) {}
^
<source>:8:17: note: void func(const S<T>&, R ...) [with X = int; T = int;
R = {int}]
inline void func(const S<T>&, R...) {}
^
<source>:14:26: error: call of overloaded 'func(S<int>, int)' is ambiguous
func<int>(S<int>(), 1); // NOK
^
...
Reproducible with 4.8.1 and 9.1. Compiles with clang (v3.0.0 and v8.0.0), icc
(v13.0.1 and v19.0.1), msvc (v19.14 and v19.20).
