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#include <iostream>
#include <vector>
using namespace std;
 
#define GC_GENERATE_IS_HAS_TYPEDEF(_arg_type)\
	template<class T>\
	class is_has_typedef_##_arg_type{\
		struct detection{};\
		static detection\
			detect(...);\
		template<class Y>\
		static typename Y::##_arg_type\
			detect(const Y &);\
	public:\
		static constexpr bool value = !std::is_same<detection, decltype(detect(std::declval<T>()))>::value;\
	};\
	template<class T>\
	constexpr bool is_has_typedef_##_arg_type##_v = is_has_typedef_##_arg_type<T>::value;
 
GC_GENERATE_IS_HAS_TYPEDEF(value_type);
 
int main() {
	// your code goes here
	std::cout << is_has_typedef_value_type_v<std::vector<int>> << ' ' << is_has_typedef_value_type_v<int>;
	return 0;
}

prog.cpp:12:20: error: pasting "::" and "value_type" does not give a valid preprocessing token
   static typename Y::##_arg_type\
                    ^
prog.cpp:20:1: note: in expansion of macro ‘GC_GENERATE_IS_HAS_TYPEDEF’
 GC_GENERATE_IS_HAS_TYPEDEF(value_type);
 ^~~~~~~~~~~~~~~~~~~~~~~~~~

Standard output is empty