+#ifndef MLIB_ARENA_H
+# include "arena.h"
+#endif
+
+/*----- Functions and macros ----------------------------------------------*/
+
+/* --- @x_alloc@ --- *
+ *
+ * Arguments: @arena *a@ = pointer to underlying arena
+ * @size_t sz@ = size of block to allocate
+ *
+ * Returns: Pointer to allocated block.
+ *
+ * Use: Allocates memory. If there's not enough memory, the
+ * exception @EXC_NOMEM@ is thrown.
+ */
+
+extern void *x_alloc(arena */*a*/, size_t /*sz*/);
+
+/* --- @x_strdup@ --- *
+ *
+ * Arguments: @arena *a@ = pointer to underlying arena
+ * @const char *s@ = pointer to a string
+ *
+ * Returns: Pointer to a copy of the string.
+ *
+ * Use: Copies a string (like @strdup@ would, if it existed). If
+ * there's not enough memory, the exception @EXC_NOMEM@ is
+ * thrown.
+ */
+
+extern char *x_strdup(arena */*a*/, const char */*s*/);
+
+/* --- @x_realloc@ --- *
+ *
+ * Arguments: @arena *a@ = pointer to underlying arena
+ * @void *p@ = pointer to a block of memory
+ * @size_t sz@ = new size desired for the block
+ * @size_t osz@ = size of the old block
+ *
+ * Returns: Pointer to the resized memory block (which is almost
+ * certainly not in the same place any more).
+ *
+ * Use: Resizes a memory block. If there's not enough memory, the
+ * exception @EXC_NOMEM@ is thrown.
+ */
+
+extern void *x_realloc(arena */*a*/, void */*p*/,
+ size_t /*sz*/, size_t /*osz*/);
+
+/* --- @x_free@ --- *
+ *
+ * Arguments: @arena *a@ = pointer to underlying arena
+ * @void *p@ = pointer to a block of memory.
+ *
+ * Returns: ---
+ *
+ * Use: Frees a block of memory.
+ */
+
+extern void x_free(arena */*a*/, void */*p*/);
+#define x_free(a, p) A_FREE(a, p)
+
+/*----- Old functions for the standard arena ------------------------------*/