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  1. #include <iostream>
  2.  
  3. template<typename T> struct Type {};
  4. typedef double lua_Number;
  5. struct lua_State {};
  6. int luaL_checkint( lua_State*, int index) {
  7. 	return 7+index;
  8. }
  9. lua_Number luaL_checknumber( lua_State*, int index) {
  10. 	return 3.14+index;
  11. }
  12. bool lua_toboolean( lua_State*, int index ) {
  13. 	return index%2 == 0;
  14. }
  15. namespace lua_to_cpp {
  16. 	inline int get(Type<int>, lua_State *l, const int index) {
  17. 		return luaL_checkint(l, index);
  18. 	};
  19.  
  20. 	inline lua_Number get(Type<lua_Number>, lua_State *l, const int index) {
  21. 		return luaL_checknumber(l, index);
  22. 	}
  23.  
  24. 	inline bool get(Type<bool>, lua_State *l, const int index) {
  25. 		return lua_toboolean(l, index) != 0;
  26. 	}
  27. }
  28. template<unsigned...>struct indexes{typedef indexes type;};
  29. template<unsigned Max, unsigned...Is>struct make_indexes:make_indexes<Max-1, Max-1, Is...>{};
  30. template<unsigned... Is>struct make_indexes<0, Is...>:indexes<Is...>{};
  31. template<unsigned Max>using make_indexes_t=typename make_indexes<Max>::type;
  32.  
  33. template<typename... Args, unsigned... Is>
  34. void invoke( void(*func)(Args...), lua_State* state, indexes<Is...>) {
  35. 	return func( lua_to_cpp::get( Type<Args>{}, state, Is+2 )... );
  36. }
  37. template<typename... Args>
  38. void invoke( void(*func)(Args...), lua_State* state ) {
  39. 	invoke( func, state, make_indexes_t<sizeof...(Args)>{} );
  40. }
  41.  
  42. void foo( int, lua_Number ) {
  43. 	std::cout << "called!\n";
  44. }
  45.  
  46. void call_foo( lua_State* state ) {
  47. 	invoke(foo, state);
  48. }
  49.  
  50.  
  51. int main() {
  52. 	call_foo(nullptr);
  53. 	// your code goes here
  54. 	return 0;
  55. }
Success #stdin #stdout 0s 3340KB
comments (?)
stdin 
Standard input is empty
stdout 
called!
https://ideone.com/B8fRw1
language:
C++14 (gcc 8.3)
created:
11 years ago
visibility:
public

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