this is what I have ended up with. combined with @Konrad Rudolph's answer and @Joachim Pileborg's comment
std::string demangled(std::string const& sym) {
std::unique_ptr<char, void(*)(void*)>
name{abi::__cxa_demangle(sym.c_str(), nullptr, nullptr, nullptr), std::free};
return {name.get()};
}
template <class T>
void print_type() {
bool is_lvalue_reference = std::is_lvalue_reference<T>::value;
bool is_rvalue_reference = std::is_rvalue_reference<T>::value;
bool is_const = std::is_const<typename std::remove_reference<T>::type>::value;
std::cout << demangled(typeid(T).name());
if (is_const) {
std::cout << " const";
}
if (is_lvalue_reference) {
std::cout << " &";
}
if (is_rvalue_reference) {
std::cout << " &&";
}
std::cout << std::endl;
};
int main(int argc, char *argv[])
{
auto f = [](auto && a, auto b) {
std::cout << std::endl;
print_type<decltype(a)>();
print_type<decltype(b)>();
};
const int i = 1;
f(i, i);
f(1, 1);
f(std::make_unique<int>(2), std::make_unique<int>(2));
auto const ptr = std::make_unique<int>();
f(ptr, nullptr);
}
and output
int const &
int
int &&
int
std::__1::unique_ptr<int, std::__1::default_delete<int> > &&
std::__1::unique_ptr<int, std::__1::default_delete<int> >
std::__1::unique_ptr<int, std::__1::default_delete<int> > const &
std::nullptr_t