memory management - Invalid Conversion for Mem Allocator Method (C) -

i'm attempting finish writing memory allocator class project, not necessary homework wasn't assigned, chose project myself.

i have 2 lines marked #1 , #2, both not work , give different error messages, here details.

i'm getting following error message (for #1): incompatible types when assigning type ‘size_t *[10]’ type ‘int *’

--- or ---

(for #2) error: incompatible types when assigning type ‘size_t *[10]’ type ‘size_t **’

i can't understand why creating empty array of same type (#2) still can't "conversion". if both arrays of type size_t*, why second error message when attempting set free_array new array?

void expandarray(void)  {     //size_t* free_array[10]; #this how free_array declared.      size_t* oldarray = free_array;     int newarray[freearraysize*2]; #1     //size_t* newarray[freearraysize*2]; #2      free_array = newarray;      int = 0;     (i=0; i<freearraysize; i++)      {         free_array[i] = oldarray[i];     }      (i=freearraysize; i<(freearraysize*2); i++)      {         free_array[i] = (size_t)null;     }      freearraysize = freearraysize*2; } 

thanks help!

your program bugged begin with. assigning free_array (which presumably global variable) point stack variable function. if solved compile issue appropriate casting operator, memory corrupted shortly after expandarray returns.

also, don't need write for-loop copy memory old array new. use memcpy() function.

this want do:

typedef unsigned char buffer_type; buffer_type* free_array = null; size_t freearraysize = 0; size_t initial_size = 100;  void expandarray() {     buffer_type* newbuffer = null;     size_t newsize = 0;     size_t oldsize = 0;      if ((freearraysize == 0) || (free_array == null))     {         newsize = initial_size;     }     else     {         newsize = freearraysize * 2;         oldsize = freearraysize;     }      // allocate new array     newbuffer = (buffer_type*)malloc(newsize*sizeof(buffer_type));      if (free_array != null)     {         // copy contents of old array new array.         memcpy(newbuffer, free_array, oldsize*sizeof(buffer_type));      }      // 0 out contents     memset(newbuffer+oldsize, '\0', (newsize-oldsize)*sizeof(buffer_type));       // make free_array point new allocation     freearraysize = newsize;     free_array = newbuffer;     free(free_array); // ok if free_array null } 

i didn't know if wanted memory buffer in "bytes" or in instances of "size_t" (as original implementation suggests). declared array of type buffer_type. can change typedef make array type want. expandarray function still work since takes sizeof(buffer_type) account memory operations.