宏定义 # 与 ## 的用法

void daba(int n){cout<<n<<endl;}//连接成标示符#define MERGEIDENT(x,y) d##x##y##x  //连接成字符串#define MERGESTRING(x,y)  "class " #x#y " info"#define STRCPY(dst,src)   strcpy(dst, #src)#define P(A) cout<<#A<<": "<<(A)<<endl;#define A1(name, type)  type name_##type##_typevoid main(){int a = 100;int b = 200;int m = 300;MERGEIDENT(a,b)(m);P(a);P(b);P(a+b);char buf[256] = "0";//strcpy(buf,MERGESTRING(m,aba));STRCPY(buf,daba);cout<<MERGESTRING(m,b)<<endl;}

//连接成标示符
#define MERGEIDENT(x,y) d##x##y##x  
//连接成字符串
#define MERGESTRING(x,y)  "class " #x#y " info"