I'm not a big fan of the NTTP used especially as e.g. for overloaded operator() the result is ambigious. What was the reason for choosing it? Besides that as Peter said the tuple/MPL list of arguments is a good idea. Another good idea is improved handling of member functions. E.g. in C++11 and up you don't only have const and noexcept but also rvalue and lvalue specifiers. So that could be added too Regards, Alex Am 12.09.20 um 20:33 schrieb Gero Peterhoff via Boost:
Hi Peter, i implemented signature_of similar to the function_traits. This is more flexible, but requires C++20.
#include <iostream> #include <cstdlib> #include <utility> #include <boost/type_traits/signature_of.hpp>
int foo(bool, float&, const uint64_t, const double&);
template <typename Type> void show_type() noexcept { std::cout << typeid(Type).name() << std::endl; } template <typename Tuple> void show_tuple_types() noexcept { auto show_elems = []<std::size_t... Idx>(const std::index_sequence<Idx...>&) noexcept { (show_type<std::tuple_element_t<Idx, Tuple>>(), ...); };
show_elems(std::make_index_sequence<std::tuple_size_v<Tuple>>{}); }
int main(const int argc, const char** args) { using sig_foo = boost::signature_of<foo>; // or &foo std::cout << "foo\n"; std::cout << "result:\t\t\t" << typeid(sig_foo::result_type).name() << std::endl; std::cout << "tuple<arguments>:\t" << typeid(sig_foo::argument_type).name() << std::endl; std::cout << "argument size:\t\t" << boost::argument_size_v<foo> << std::endl; std::cout << "argument types are:\n"; show_tuple_types<typename sig_foo::argument_type>();
using sig_baz = boost::signature_of<&bar::baz>; std::cout << "\nbaz\n"; std::cout << "result:\t\t\t" << typeid(sig_baz::result_type).name() << std::endl; std::cout << "tuple<arguments>:\t" << typeid(sig_baz::argument_type).name() << std::endl; std::cout << "argument size:\t\t" << boost::argument_size_v<&bar::baz> << std::endl; std::cout << "argument types are:\n"; show_tuple_types<typename sig_baz::argument_type>();
return EXIT_SUCCESS; }
(Hint: typeid ignore references)
regards Gero