  * Test texture transform iterator
  */
 template <typename T, typename CastT>
-void TestTexTransform(char *type_string)
+void TestTexTransform(const char *type_string)
 {
     printf("\nTesting tex-transform iterator on type %s\n", type_string); fflush(stdout);
 

 * Test constant iterator
 */
template <typename T>
void TestConstant(T base, char *type_string)
{
    printf("\nTesting constant iterator on type %s (base: %d)\n", type_string, int(base)); fflush(stdout);


 * Test tex-ref texture iterator
 */
template <typename T, typename CastT>
void TestTexRef(const char *type_string)
{
    printf("\nTesting tex-ref iterator on type %s\n", type_string); fflush(stdout);

