c++ - Why my token-pasting usage doesn't work? -

i made declaration below.

#define func_dec(f) inline void f##(){}  class myclass { public:     func_dec(a);     func_dec(b); }; 

after preprocessing, expected class looked like:

class myclass { public:     inline void a(){};     inline void b(){}; }; 

while actually, got compiling errors

#20 identifier "a" undefined #20 identifier "b" undefined  warnings description resource    path    location    type #891-d omission of explicit type nonstandard ("int" assumed) 

can tell me what's wrong declaration? thank much.

in case, don't need use ## operator.

#define func_dec(f) inline void f(){} 

is fine.

it concatenation operator, useful kind of case:

#define func_dec(f) inline void funcdec##f(){} //                              ^^^^^^^^^^ 

who expanded as:

inline void funcdeca(){}   // func_dec(a) 

just say: code works fine on visual studio.