Why allow concatenation of string literals?

Question

I was recently bitten by a subtle bug.

char ** int2str = {
   \"zero\", // 0
   \"one\",  // 1
   \"two\"   // 2
   \"three\",// 3
   nullptr };

assert( int         


        

Answer 1

It's a great feature that allows you to combine preprocessor strings with your strings.

// Here we define the correct printf modifier for time_t
#ifdef TIME_T_LONG
    #define TIME_T_MOD "l"
#elif defined(TIME_T_LONG_LONG)
    #define TIME_T_MOD "ll"
#else
    #define TIME_T_MOD ""
#endif

// And he we merge the modifier into the rest of our format string
printf("time is %" TIME_T_MOD "u\n", time(0));