1 files changed, 7 insertions, 0 deletions
diff --git a/devel.but b/devel.but
index 71bc60d..209c501 100644
--- a/devel.but
+++ b/devel.but
@@ -5330,6 +5330,13 @@ This macro, defined in the main Puzzles header file, strips the
 modifier flags from the key code passed as an argument. It is
 equivalent to a bitwise-AND with \cw{~MOD_MASK}.
 
+\S{utils-swap-regions} \cw{swap_regions()}
+
+\c void swap_regions(void *av, void *bv, size_t size);
+
+Swap two regions of memory of \cw{size} bytes. The two regions must
+not overlap.
+
 \C{writing} How to write a new puzzle
 
 This chapter gives a guide to how to actually write a new puzzle: