add: change implementation of max_align_t from sizeof to alignment_of

cleeus · Jul 31, 2012 · d1006f6 · d1006f6
1 parent b5080a4
commit d1006f6
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Showing 2 changed files with 25 additions and 24 deletions.
diff --git a/arena_test.cpp b/arena_test.cpp
@@ -18,26 +18,26 @@ using boost::arena::obstack;
 BOOST_AUTO_TEST_SUITE(arena_all)
 
 
-BOOST_AUTO_TEST_CASE(max_sizeof_char_double) {
+BOOST_AUTO_TEST_CASE(max_alignof_char_double) {
 	typedef char T1;
 	typedef double T2;
-	typedef typename boost::arena::detail::max_sizeof<T1,T2> Tmax;
+	typedef typename boost::arena::detail::max_alignof<T1,T2> Tmax;
 
 	BOOST_CHECK( sizeof(Tmax::type) == sizeof(T2) );
 	BOOST_CHECK( Tmax::value == sizeof(T2) );
 }
 
-BOOST_AUTO_TEST_CASE(max_sizeof_double_char) {
+BOOST_AUTO_TEST_CASE(max_alignof_double_char) {
 	typedef double T1;
 	typedef char T2;
-	typedef typename boost::arena::detail::max_sizeof<T1,T2> Tmax;
+	typedef typename boost::arena::detail::max_alignof<T1,T2> Tmax;
 
 	BOOST_CHECK( sizeof(Tmax::type) == sizeof(T1) );
 	BOOST_CHECK( Tmax::value == sizeof(T1) );
 }
 
-BOOST_AUTO_TEST_CASE(max_sizeof_9_char_int) {
-	typedef typename boost::arena::detail::max_sizeof<
+BOOST_AUTO_TEST_CASE(max_alignof_9_char_int) {
+	typedef typename boost::arena::detail::max_alignof<
 		char,
 		char,
 		char,
@@ -54,8 +54,8 @@ BOOST_AUTO_TEST_CASE(max_sizeof_9_char_int) {
 	BOOST_CHECK( Tmax::value == sizeof(int) );
 }
 
-BOOST_AUTO_TEST_CASE(max_sizeof_9_char_int_reverse) {
-	typedef typename boost::arena::detail::max_sizeof<
+BOOST_AUTO_TEST_CASE(max_alignof_9_char_int_reverse) {
+	typedef typename boost::arena::detail::max_alignof<
 		int,
 		char,
 		char,

diff --git a/max_alignment_type.hpp b/max_alignment_type.hpp
@@ -2,22 +2,23 @@
 #define BOOST_MAXALIGNMENT_TYPE_HPP
 
 #include <boost/cstdint.hpp>
+#include <boost/type_traits/alignment_of.hpp>
 
 namespace boost {
 namespace arena {
 namespace detail {
 
 template<typename T1, typename T2, bool T1gtT2>
-struct max_sizeof_impl {
+struct max_alignof_impl {
 	typedef T1 type;
-	enum { value = sizeof(type) };
+	enum { value = alignment_of<type>::value };
 };
 
 //partial specialization on false
 template<typename T1, typename T2>
-struct max_sizeof_impl<T1,T2,false> {
+struct max_alignof_impl<T1,T2,false> {
 	typedef T2 type;
-	enum { value = sizeof(type) };
+	enum { value = alignment_of<type>::value };
 };
 
 struct null_type {};
@@ -34,21 +35,21 @@ template<
 	typename T9 = null_type,
 	typename T10 = null_type
 >
-struct max_sizeof {
+struct max_alignof {
 private:
-	typedef typename max_sizeof<T2,T3,T4,T5,T6,T7,T8,T9,T10>::type end_max_type;
-	typedef max_sizeof<T1,end_max_type> total_max_sizeof;
+	typedef typename max_alignof<T2,T3,T4,T5,T6,T7,T8,T9,T10>::type back_type;
+	typedef max_alignof<T1,back_type> total_type;
 
-	typedef typename total_max_sizeof::type max_type;
-	enum { max_value = total_max_sizeof::value };
+	typedef typename total_type::type max_type;
+	enum { max_value = total_type::value };
 public:
 	typedef max_type type;
 	enum { value = max_value };
 };
 
 
 template<typename T1>
-struct max_sizeof<
+struct max_alignof<
 	T1,
 	null_type,
 	null_type,
@@ -62,12 +63,12 @@ struct max_sizeof<
 >
 {
 	typedef T1 type;
-	enum { value = sizeof(type) };
+	enum { value = alignment_of<type>::value };
 };
 
 
 template<typename T1, typename T2>
-struct max_sizeof<
+struct max_alignof<
 	T1,
 	T2,
 	null_type,
@@ -81,9 +82,9 @@ struct max_sizeof<
 >
 {
 private:
-	typedef max_sizeof_impl<T1,T2, (sizeof(T1)>sizeof(T2)) > total_max_sizeof;
-	typedef typename total_max_sizeof::type max_type;
-	enum { max_value = total_max_sizeof::value };
+	typedef max_alignof_impl<T1,T2, (alignment_of<T1>::value > alignment_of<T2>::value) > total_type;
+	typedef typename total_type::type max_type;
+	enum { max_value = total_type::value };
 public:
 	typedef max_type type;
 	enum { value = max_value };
@@ -93,7 +94,7 @@ struct max_sizeof<
 } //namespace detail
 
 
-typedef detail::max_sizeof<
+typedef detail::max_alignof<
 	char,
 	short,
 	int,