add iarray

array/iarray_get.c

@@ -0,0 +1,12 @@
+#include "iarray.h"
+
+void* iarray_get(iarray* ia,size_t pos) {
+  char* x;
+  size_t y;
+  if (!ia->pages) return 0;
+  y=pos/ia->elemperpage;
+  if (y>=ia->pagefence) return 0;
+  x=ia->pages[y];
+  if (!x) return 0;
+  return x+(pos%ia->elemperpage)*ia->elemsize;
+}