From 182342fb3e6ecbe1b51f786acd650c774248ac78 Mon Sep 17 00:00:00 2001
From: ilor <kailoran@gmail.com>
Date: Wed, 9 Mar 2011 12:37:37 +0100
Subject: [PATCH] use safe_bool in Value's Bool to allow if(b) constructs
---
libwccl/values/bool.h | 11 +++++++++++
tests/values.cpp | 18 ++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/libwccl/values/bool.h b/libwccl/values/bool.h
index 53393fb..a915213 100644
--- a/libwccl/values/bool.h
+++ b/libwccl/values/bool.h
@@ -39,6 +39,17 @@ public:
return val_ ? "True" : "False";
}
+ typedef void (Bool::*safe_bool)() const;
+ void safe_bool_helper() const {}
+
+ operator safe_bool() const {
+ return val_ ? &Bool::safe_bool_helper : 0;
+ }
+
+ bool operator!() const {
+ return !val_;
+ }
+
private:
bool val_;
};
diff --git a/tests/values.cpp b/tests/values.cpp
index d87c1b1..837e1e2 100644
--- a/tests/values.cpp
+++ b/tests/values.cpp
@@ -188,4 +188,22 @@ BOOST_AUTO_TEST_CASE(position_ops)
BOOST_CHECK(end.equals(minus_one, sc));
}
+BOOST_AUTO_TEST_CASE(bool_safe_bool)
+{
+ Bool b(false);
+ BOOST_CHECK(!b);
+ if (b) {
+ BOOST_ERROR("if (b) on Bool(false)");
+ }
+ b.set_value(true);
+ if (!b) {
+ BOOST_ERROR("if (!b) on Bool(true)");
+ }
+ if (b) {
+ } else {
+ BOOST_ERROR("if (b) else reached on Bool(true)");
+ }
+ BOOST_CHECK(b);
+}
+
BOOST_AUTO_TEST_SUITE_END()
--
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