Help! I need to reallocating memory then set the entire/partial buffer into specific value.

calloc only works for allocating memory, not reallocating memory
and memset only works for char data type... T_T...

Should I do:
Code:
  buffer <- malloc(5)

  for i <- 0 to 4
    buffer[i] <- 2
  end for

  ; do something with buffer[i]

  buffer <- realloc(10)

  for i <- 5 to 9
    buffer[i] <- 2
  end for
Or any std function out there?

Btw, we should prefer to use std function instead of our function because they are faster sometime.