From 0a497a27658d5b7b7b77ab7817d7af56d831f40c Mon Sep 17 00:00:00 2001
From: Jan Nieuwenhuizen <janneke@gnu.org>
Date: Sun, 17 Jul 2016 13:32:52 +0200
Subject: [PATCH] mes.c: add boolean_p.

---
 mes.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mes.c b/mes.c
index 119979bc..655abf0b 100644
--- a/mes.c
+++ b/mes.c
@@ -477,6 +477,12 @@ builtin_p (scm *x)
     ? &scm_t : &scm_f;
 }
 
+scm *
+boolean_p (scm *x)
+{
+  return (x == &scm_t || x == &scm_f) ? &scm_t : &scm_f;
+}
+
 scm *
 char_p (scm *x)
 {