使用Boost獲取成員函數的參數和參數類型？ （boost :: function_traits）

Question

它工作得很好，對於普通的香草函數。下面的代碼工作得很好。它打印出究竟什麼是應該：

int __cdecl(int, char) 
2 
int,char 

---

#include <boost/type_traits.hpp> 
#include <boost/function.hpp> 
#include <boost/typeof/std/utility.hpp> 

#include <iostream> 

using std::cout; 
using std::endl; 

int foo(int, char) { 
return 0; 
} 
int main() { 
    typedef BOOST_TYPEOF(foo) foo_type;; 
    typedef boost::function_traits<foo_type> function_traits; 

    cout << typeid(foo_type).name() << endl; 
    cout << function_traits::arity << endl; 
    cout << typeid(function_traits::arg1_type).name() << ","; 
    cout << typeid(function_traits::arg2_type).name() << endl; 

    return 0; 
} 

那麼，問題是，怎麼能做到這一點，如果foo是類酒吧的成員函數？

struct bar { 
    int foo(int, char) { return 0; } 
}; 

我嘗試了這些結構的無數組合：BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP（）BOOST_TYPEOF_REGISTER_TYPE（）的boost ::裁判的boost :: remove_pointer的boost ::綁定的boost ::的mem_fn

等等，等等......沒有喜悅。

Answer 1

Boost Function Types很可能是自然的解決方案：

#include <boost/function_types/function_type.hpp> 
#include <boost/function_types/parameter_types.hpp> 
#include <boost/function_types/function_arity.hpp> 
#include <boost/typeof/std/utility.hpp> 
#include <iostream> 

struct bar { 
    int foo(int, char) { return 0; } 
}; 

int main() { 

    typedef BOOST_TYPEOF(&bar::foo) foo_type; 

    std::cout << typeid(foo_type).name() << std::endl; 
    std::cout << boost::function_types::function_arity<foo_type>::value << std::endl; 
    std::cout << typeid(boost::mpl::at_c<boost::function_types::parameter_types<foo_type>,1>::type).name() << ","; 
    std::cout << typeid(boost::mpl::at_c<boost::function_types::parameter_types<foo_type>,2>::type).name() << ","; 

    return 0; 
} 

Answer 2

科內爾·基利爾威奇斯釘它。這裏將解決方案與測試消息分開。

#include <boost/function_types/function_type.hpp> 
#include <boost/function_types/parameter_types.hpp> 
#include <boost/function_types/function_arity.hpp> 
#include <boost/typeof/std/utility.hpp> 
#include <iostream> 

struct bar { 
    int foo(int, char) { return 0; } 
}; 

int main() { 

    typedef BOOST_TYPEOF(&bar::foo) 
     foo_type; 
    int arity = boost::function_types::function_arity<foo_type>::value; 
    typedef boost::mpl::at_c<boost::function_types::parameter_types<foo_type>,1>::type 
     arg1; 
    typedef boost::mpl::at_c<boost::function_types::parameter_types<foo_type>,2>::type 
     arg2; 

    std::cout << typeid(foo_type).name() << std::endl; 
    std::cout << arity << std::endl; 
    std::cout << typeid(arg1).name() << ","; 
    std::cout << typeid(arg2).name() << std::endl; 
    return 0; 
}