https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64194
--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Slightly different testcase from PR 69620 which is probably the same issue:
struct function {
template<typename F>
function(F);
};
template <typename T1, typename T2>
auto sum(T1 x, T2 y)
{
return x + y;
}
template <typename T1, typename T2, typename... Targ>
auto sum(T1 x, T2 y, Targ... args)
{
return sum(x + y, args...);
}
int main()
{
//(void)sum<int, int, int>;
function f = sum<int, int, int>;
}
ded.cc: In function 'int main()':
ded.cc:21:18: error: conversion from '<unresolved overloaded function type>' to
non-scalar type 'function' requested
function f = sum<int, int, int>;
^~~~~~~~~~~~~~~~~~
It works if the function is instantiated first by uncommenting the first line
in main.
