X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/sod/blobdiff_plain/dea6ee94a659dbe4794fa450037664781009d4eb..refs/heads/mdw/progfmt:/src/builtin.lisp

diff --git a/src/builtin.lisp b/src/builtin.lisp
index d07f539..6310741 100644
--- a/src/builtin.lisp
+++ b/src/builtin.lisp
@@ -278,6 +278,16 @@ 	      (default (sod-initarg-default initarg)))
     list))
 
 (definst suppliedp-struct (stream) (flags var)
+  "Declare a `suppliedp' structure VAR containing a bit for each named FLAG.
+
+   The output looks like this:
+
+	struct {
+	  unsigned FLAG: 1;
+	  /* ... */
+	} VAR;
+
+   Note that this will not be valid C unless there is at least one flag."
   (format stream
 	  "~@<struct { ~2I~_~{unsigned ~A: 1;~^ ~_~} ~I~_} ~A;~:>"
 	  flags var))