gistfile1.hpp

#include <stdlib.h>
#include <iostream>
#include <string>
#include <typeinfo>
#include <cxxabi.h>

template<typename Tretval_, typename Targ1_, typename Targ2_>
struct signature
{
    typedef Tretval_ retval_type;
    typedef Targ1_ arg1_type;
    typedef Targ2_ arg2_type;
};

template<typename Tretval_, typename Targ1_, typename Targ2_>
signature<Tretval_, Targ1_, Targ2_>
get_function_signature(Tretval_(*)(Targ1_, Targ2_))
{
    return signature<Tretval_, Targ1_, Targ2_>();
}

template<typename Tretval_, typename Targ1_>
signature<Tretval_, Targ1_, void>
get_function_signature(Tretval_(*)(Targ1_))
{
    return signature<Tretval_, Targ1_, void>();
}

template<typename Tretval_>
signature<Tretval_, void, void>
get_function_signature(Tretval_(*)())
{
    return signature<Tretval_, void, void>();
}

std::string demangled_name(std::type_info const& info)
{
    std::string buf;
    int status;
    char* demangled_name = __cxxabiv1::__cxa_demangle(info.name(), 0, 0, &status);
    if (status == 0) {
        buf = std::string(demangled_name);
        free(demangled_name);
    } else {
        buf = std::string("<<unknown>>");
    }
    return buf;
}

template<typename T_>
void print_signature(T_ const&)
{
    std::cout << "retval: " << demangled_name(typeid(typename T_::retval_type)) << std::endl;
    std::cout << "arg1: " << demangled_name(typeid(typename T_::arg1_type)) << std::endl;
    std::cout << "arg2: " << demangled_name(typeid(typename T_::arg2_type)) << std::endl;
}

int main(int, char**)
{
    print_signature(get_function_signature(&realloc));
    print_signature(get_function_signature(&sleep));
    print_signature(get_function_signature(&getpagesize));
    return 0;
}