Documentation / technical / api-allocation-growing.txton commit Merge git://git.kernel.org/pub/scm/gitk/gitk (75b4406)
   1allocation growing API
   2======================
   3
   4Dynamically growing an array using realloc() is error prone and boring.
   5
   6Define your array with:
   7
   8* a pointer (`ary`) that points at the array, initialized to `NULL`;
   9
  10* an integer variable (`alloc`) that keeps track of how big the current
  11  allocation is, initialized to `0`;
  12
  13* another integer variable (`nr`) to keep track of how many elements the
  14  array currently has, initialized to `0`.
  15
  16Then before adding `n`th element to the array, call `ALLOC_GROW(ary, n,
  17alloc)`.  This ensures that the array can hold at least `n` elements by
  18calling `realloc(3)` and adjusting `alloc` variable.
  19
  20------------
  21sometype *ary;
  22size_t nr;
  23size_t alloc
  24
  25for (i = 0; i < nr; i++)
  26        if (we like ary[i] already)
  27                return;
  28
  29/* we did not like any existing one, so add one */
  30ALLOC_GROW(ary, nr + 1, alloc);
  31ary[nr++] = value you like;
  32------------
  33
  34You are responsible for updating the `nr` variable.