Subject: [Boost-commit] svn:boost r51452 - sandbox/mirror/boost/mirror/detail
From: chochlik_at_[hidden]
Date: 2009-02-26 10:32:03
Author: matus.chochlik
Date: 2009-02-26 10:32:02 EST (Thu, 26 Feb 2009)
New Revision: 51452
URL: http://svn.boost.org/trac/boost/changeset/51452
Log:
[mirror 0.3.x]
- minor bugfix of offset_of
Text files modified:
sandbox/mirror/boost/mirror/detail/meta_attribs_base.hpp | 36 ++++++++++++++++++++++++++++++++----
1 files changed, 32 insertions(+), 4 deletions(-)
Modified: sandbox/mirror/boost/mirror/detail/meta_attribs_base.hpp
==============================================================================
--- sandbox/mirror/boost/mirror/detail/meta_attribs_base.hpp (original)
+++ sandbox/mirror/boost/mirror/detail/meta_attribs_base.hpp 2009-02-26 10:32:02 EST (Thu, 26 Feb 2009)
@@ -23,6 +23,7 @@
// necessary type traits
#include <boost/call_traits.hpp>
#include <boost/type_traits/is_pod.hpp>
+#include <boost/type_traits/alignment_of.hpp>
// enable if
#include <boost/utility/enable_if.hpp>
//
@@ -555,6 +556,34 @@
typedef unsigned char byte;
typedef const byte* byte_ptr;
+ template <class T>
+ struct dummy_instance
+ {
+ inline T* ptr(void) const
+ {
+ return reinterpret_cast<T*>(
+ ::boost::alignment_of<T>::value
+ );
+ }
+
+ inline operator T& (void) const
+ {
+ T* pointer(ptr());
+ return *pointer;
+ }
+
+ inline operator const T& (void) const
+ {
+ const T* pointer(ptr());
+ return *pointer;
+ }
+
+ inline T* operator & (void) const
+ {
+ return ptr();
+ }
+ };
+
static inline ptrdiff_t invalid_offset(void)
{
return -1;
@@ -598,7 +627,7 @@
// this can be a problem with pod-types
// meta-types of which have custom implementation
// of address(...) expecting a valid instance
- T* pointer(0);
+ dummy_instance<T> instance;
//
// otherwise something like the following will
// be necessary:
@@ -607,7 +636,7 @@
//T* pointer((T*)alloc.allocate(1));
// ...
// alloc.deallocate(pointer, 1);
- return offset(*pointer, pos);
+ return offset(instance, pos);
}
template <class T, int I>
@@ -668,8 +697,7 @@
template <int I>
static inline ptrdiff_t offset_of(mpl::int_<I> pos)
{
- Class* ptr(0);
- return get_offset_of(pos, ptr);
+ return get_offset_of(pos, (Class*)0);
}
};