[Bug driver/85493] decltype can use deleted constructor and deleted template function in template function

[ihorelo at mail dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85493

--- Comment #2 from Ihor Rudynskyi <ihorelo at mail dot ru> ---
Summarizing:

g++ 7.2 allows to write this code.

struct no_def
{
        no_def() = delete;
};

template<typename...>
int foo() = delete;

template<typename...>
void test()
{
    decltype(no_def()) a1{};
    decltype(no_def(1,2,3)) a2{};
    decltype(foo<>()) a3{};
}

int main()
{
        test<>();
}

but according to godbolt a3 case seems to have been fixed on trunk