c/string/byte/memset

@1@Copies the value into each of the first  characters of the object pointed to by. @@The behavior is undefined if access occurs beyond the end of the dest array. The behavior is undefined if is a null pointer. @2@ Same as, except that is safe for sensitive information. @3@ Same as, except that the following errors are detected at runtime and call the currently installed constraint handler function after storing in every location of the destination range  if  and  are themselves valid:
 * is a null pointer
 * or is greater than rsize_max
 * is greater than (buffer overflow would occur)

@@The behavior is undefined if the size of the character array pointed to by <  <= ; in other words, an erroneous value of  does not expose the impending buffer overflow.

Return value
@1,2@ A copy of @3@ zero on success, non-zero on error. Also on error, if is not a null pointer and  is valid, writes  fill bytes  to the destination array.