c++ - Need to fix my Variadic Macros -

i want use variadic macros errors

#define server_re_1(serverfunction, type1)                          \     {                                                               \         type1 arg1;                                                 \         getdata(args, arg1);                                        \         sv. ## serverfunction ## (ssl, arg1);                       \     }  #define server_re_2(serverfunction, type1, type2)                   \     {                                                               \         type1 arg1;                                                 \         type2 arg2;                                                 \         getdata(args, arg1, arg2);                                  \         sv. ## serverfunction ## (ssl, arg1, arg2);                 \     }  #define server_re_3(serverfunction, type1, type2, type3)            \     {                                                               \         type1 arg1;                                                 \         type2 arg2;                                                 \         type3 arg3;                                                 \         getdata(args, arg1, arg2, arg3);                            \         sv. ## serverfunction ## (ssl, arg1, arg2, arg3);           \     }  #define get_macro(_1,_2,_3,_4,name,...) name #define server_re(...) get_macro(__va_args__, server_re_3, server_re_2, server_re_1)(__va_args__) 

-

server_re(signin, std::string, std::string); 

error c2065: 'signin' : undeclared identifier
error c2275: 'std::string' : illegal use of type expression

-

but server_re_2 works good.

server_re2(signin, std::string, std::string); 

remove ##, in replace lines

    sv. ## serverfunction ## (ssl, arg1, arg2, arg3);           \ 

with

    sv. serverfunction (ssl, arg1, arg2, arg3);           \ 

edit

can try compile following code?

#include <string> #define server_re_1(serverfunction, type1)                          \     {                                                               \         type1 arg1;                                                 \         getdata(args, arg1);                                        \         sv. serverfunction (ssl, arg1);                       \     }  #define server_re_2(serverfunction, type1, type2)                   \     {                                                               \         type1 arg1;                                                 \         type2 arg2;                                                 \         getdata(args, arg1, arg2);                                  \         sv.serverfunction(ssl, arg1, arg2);                 \     }  #define server_re_3(serverfunction, type1, type2, type3)            \     {                                                               \         type1 arg1;                                                 \         type2 arg2;                                                 \         type3 arg3;                                                 \         getdata(args, arg1, arg2, arg3);                            \         sv.serverfunction(ssl, arg1, arg2, arg3);           \     }  #define get_macro(_1,_2,_3,_4,name,...) name #define server_re(...) get_macro(__va_args__, server_re_3, server_re_2, server_re_1)(__va_args__)  struct c{   template<class t1>   void signin(int,t1){}   template<class t1, class t2>   void signin(int,t1,t2){}   template<class t1, class t2,class t3>   void signin(int,t1,t2,t3){} };  template<class t1> void getdata(int,t1){} template<class t1, class t2> void getdata(int,t1,t2){} template<class t1, class t2, class t3> void getdata(int,t1,t2,t3){}  int main(){   c sv;   int args=0,ssl=0;   server_re(signin, std::string);   server_re(signin, std::string, std::string);   server_re(signin, std::string, std::string, std::string); } 

this full code compiles - - me in both g++ , clang++, in both c++11 , c++98 modes

edit 2

that first warning warning c4003 makes me think there basic problem variadic macros here.

indeed, booting windows , playing around in visual studio, there bug in visual studio in variadic macro expantion.

you can see following code:

#include <stdio.h> #define aaa(a,b) printf("%d %d\n",a,b) #define bbb(...) aaa(__va_args__) int main(){   aaa(1,2); // works   bbb(3,4); // warning + error } 

but worry not! can fix it! use above code, replace line

#define server_re(...) get_macro(__va_args__, server_re_3, server_re_2, server_re_1)(__va_args__) 

with

#define get_macro_x(x) get_macro x #define server_re(...) get_macro_x((__va_args__, server_re_3, server_re_2, server_re_1))(__va_args__) 

and compiles in visual studio! yay!