From e0bc5811a3c9726cc5b2dc804a7e8915c39d3dbd Mon Sep 17 00:00:00 2001
From: Leandro Lucarella <llucarella@integratech.com.ar>
Date: Mon, 1 Dec 2008 16:51:27 -0200
Subject: [PATCH] Add reverse iteration to basic_buffer

Reverse iteration was broken in basic_buffer, and thus commented out. Now
the reverse iterators are defined properly and all seems to work fine
according to the added test cases for reverse iteration.
---
 src/basic_buffer.hpp | 24 +++++++++++-------------
 test/buffer.cpp      | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 13 deletions(-)

diff --git a/src/basic_buffer.hpp b/src/basic_buffer.hpp
index 873a999..1e53f96 100644
--- a/src/basic_buffer.hpp
+++ b/src/basic_buffer.hpp
@@ -36,7 +36,7 @@ struct basic_buffer {
 	typedef const value_type& const_reference;
 
 	///
-	typedef value_type* iterator; // TODO: make a real iterator
+	typedef value_type* iterator;
 
 	///
 	typedef const value_type* const_iterator;
@@ -54,12 +54,10 @@ struct basic_buffer {
 	typedef const pointer const_pointer;
 
 	///
-	// TODO: reverse iterator
-	//typedef typename std::reverse_iterator< iterator > reverse_iterator;
+	typedef std::reverse_iterator< iterator > reverse_iterator;
 
 	///
-	//typedef typename std::reverse_iterator< const iterator >
-	//		const_reverse_iterator;
+	typedef std::reverse_iterator< const_iterator > const_reverse_iterator;
 
 
 	// Construct/Copy/Destroy
@@ -179,29 +177,29 @@ struct basic_buffer {
 	 * Returns a random access reverse_iterator that points to the
 	 * past-the-end value.
 	 */
-	//reverse_iterator rbegin()
-	//{ return std::reverse_iterator< iterator >(end()); }
+	reverse_iterator rbegin()
+	{ return reverse_iterator(end()); }
 
 	/**
 	 * Returns a random access const_reverse_iterator that points to the
 	 * past-the-end value.
 	 */
-	//const_reverse_iterator rbegin() const
-	//{ return std::reverse_iterator< const iterator >(end()); }
+	const_reverse_iterator rbegin() const
+	{ return const_reverse_iterator(end()); }
 
 	/**
 	 * Returns a random access reverse_iterator that points to the first
 	 * element.
 	 */
-	//reverse_iterator rend()
-	//{ return std::reverse_iterator< iterator >(begin()); }
+	reverse_iterator rend()
+	{ return reverse_iterator(begin()); }
 
 	/**
 	 * Returns a random access const_reverse_iterator that points to the
 	 * first element.
 	 */
-	//const_reverse_iterator rend() const
-	//{ return std::reverse_iterator< const iterator >(begin()); }
+	const_reverse_iterator rend() const
+	{ return const_reverse_iterator(begin()); }
 
 
 	// Capacity
diff --git a/test/buffer.cpp b/test/buffer.cpp
index f455ea5..9a0039c 100644
--- a/test/buffer.cpp
+++ b/test/buffer.cpp
@@ -23,6 +23,8 @@ std::ostream& operator << (std::ostream& os, const posixx::buffer& b)
 BOOST_TEST_DONT_PRINT_LOG_VALUE( buffer ) // FIXME
 BOOST_TEST_DONT_PRINT_LOG_VALUE( buffer::iterator )
 BOOST_TEST_DONT_PRINT_LOG_VALUE( buffer::const_iterator )
+BOOST_TEST_DONT_PRINT_LOG_VALUE( buffer::reverse_iterator )
+BOOST_TEST_DONT_PRINT_LOG_VALUE( buffer::const_reverse_iterator )
 
 // avoid compilation warning concerning unused variables
 void dummy(buffer::const_iterator i) {}
@@ -241,6 +243,37 @@ BOOST_AUTO_TEST_CASE( iterators_test )
 	BOOST_CHECK_EQUAL(*(b.begin() + 1), 77);
 }
 
+BOOST_AUTO_TEST_CASE( reverse_iterators_test )
+{
+	buffer::value_type a[] = { 56, 123, 253 };
+	buffer b(a, a + 3);
+	BOOST_CHECK_NE(b.rbegin(), b.rend());
+	BOOST_CHECK_LT(b.rbegin(), b.rend());
+	buffer::reverse_iterator i = b.rbegin();
+	BOOST_CHECK_EQUAL(*i, 253);
+	i++;
+	BOOST_CHECK_EQUAL(*i, 123);
+	++i;
+	BOOST_CHECK_EQUAL(*i, 56);
+	i += 1;
+	BOOST_CHECK_EQUAL(i, b.rend());
+	i--;
+	BOOST_CHECK_EQUAL(*i, 56);
+	--i;
+	BOOST_CHECK_EQUAL(*i, 123);
+	i -= 1;
+	BOOST_CHECK_EQUAL(*i, 253);
+	i++;
+	BOOST_CHECK_EQUAL(*(i + 1), 56);
+	BOOST_CHECK_EQUAL(*(i - 1), 253);
+	BOOST_CHECK_EQUAL(i - 1, b.rbegin());
+	BOOST_CHECK_EQUAL(i + 2, b.rend());
+	BOOST_CHECK_EQUAL(i - b.rbegin(), 1);
+	*i = 77;
+	BOOST_CHECK_EQUAL(*i, 77);
+	BOOST_CHECK_EQUAL(*(b.rbegin() + 1), 77);
+}
+
 BOOST_AUTO_TEST_CASE( resize_test )
 {
 	buffer b;
-- 
2.43.0