+XBT_PUBLIC(xbt_matrix_t) xbt_matrix_new(int lines, int rows, const unsigned long elmsize, void_f_pvoid_t const free_f);
+XBT_PUBLIC(xbt_matrix_t) xbt_matrix_new_sub(xbt_matrix_t from, int lsize, int rsize, int lpos, int rpos,
+ pvoid_f_pvoid_t const cpy_f);
+XBT_PUBLIC(void) xbt_matrix_free(xbt_matrix_t matrix);