From dc06c88758560f6c7f320fbddc3d6424c2c1249e Mon Sep 17 00:00:00 2001
From: Heinz Mauelshagen <heinzm@redhat.com>
Date: Wed, 23 Jan 2013 14:39:42 +0100
Subject: [PATCH] Joe's BOOST_STATIC_ASSERT addition

---
 persistent-data/buffer.h | 10 +++++++++-
 unit-tests/buffer_t.cc   | 15 +++++----------
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/persistent-data/buffer.h b/persistent-data/buffer.h
index 45e2390..051db59 100644
--- a/persistent-data/buffer.h
+++ b/persistent-data/buffer.h
@@ -26,6 +26,7 @@
 #include <boost/noncopyable.hpp>
 #include <boost/optional.hpp>
 #include <boost/shared_ptr.hpp>
+#include <boost/static_assert.hpp>
 
 #include <stdexcept>
 
@@ -43,6 +44,9 @@ namespace persistent_data {
 	template <uint32_t Size = DEFAULT_BUFFER_SIZE, uint32_t Alignment = 512>
 	class buffer : private boost::noncopyable {
 	public:
+		BOOST_STATIC_ASSERT_MSG((Alignment > 1) & !(Alignment & (Alignment - 1)),
+					"Alignment must be a power of two.");
+
 		typedef boost::shared_ptr<buffer> ptr;
 		typedef boost::shared_ptr<buffer const> const_ptr;
 
@@ -73,7 +77,11 @@ namespace persistent_data {
 			// Allocates size bytes and returns a pointer to the
 			// allocated memory. The memory address will be a
 			// multiple of 'Alignment', which must be a power of two
-			return memalign(Alignment, s);
+			void *mem = memalign(Alignment, s);
+			if (!mem)
+				throw std::bad_alloc();
+
+			return mem;
 		}
 
 		static void operator delete(void *p) {
diff --git a/unit-tests/buffer_t.cc b/unit-tests/buffer_t.cc
index a5d98a5..382b4da 100644
--- a/unit-tests/buffer_t.cc
+++ b/unit-tests/buffer_t.cc
@@ -79,24 +79,18 @@ BOOST_AUTO_TEST_CASE(buffer_8_a_8_access)
 	buffer<sz, align>::ptr b = create_buffer<sz, align>();
 
 	(*b)[0] = 0;
-	BOOST_CHECK_EQUAL((*b)[0], '\0');
-}
-
-BOOST_AUTO_TEST_CASE(buffer_8_a_8_oob)
-{
-	uint32_t const sz = 8, align = 8;
-	buffer<sz, align>::ptr b = create_buffer<sz, align>();
-
-	BOOST_CHECK_NO_THROW((*b)[8] = 0);
+	BOOST_CHECK_EQUAL((*b)[0], 0);
 }
 
+#if 0
 BOOST_AUTO_TEST_CASE(buffer_8_a_8_const_access)
 {
 	uint32_t const sz = 8, align = 8;
 	buffer<sz, align>::const_ptr b = create_buffer<sz, align>();
 
-	// (*b)[0] = 0; // Compile time error accessing read-only location 
+	(*b)[0] = 0; // Compile time error accessing read-only location 
 }
+#endif
 
 // 8 byte buffer size, varying alignment from 1 - 7
 BOOST_AUTO_TEST_CASE(buffer_128_a_1_fails)
@@ -105,6 +99,7 @@ BOOST_AUTO_TEST_CASE(buffer_128_a_1_fails)
 	buffer<sz, align>::ptr b = create_buffer<sz, align>();
 
 	BOOST_CHECK(!b);
+	BOOST_CHECK_EQUAL((unsigned long) b->raw() & (align - 1), 1);
 }
 
 BOOST_AUTO_TEST_CASE(buffer_128_a_2_succeeds)