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Code refactoring: removed private base classes of value_initialized, as suggested by Fernando Cacciola.

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[SVN r41216]
This commit is contained in:
Niels Dekker 2007-11-18 22:11:57 +00:00
parent b3a971e7e9
commit ec46e40809
1 changed files with 41 additions and 98 deletions
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137
include/boost/utility/value_init.hpp
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@ -6,6 +6,7 @@
//
// 21 Ago 2002 (Created) Fernando Cacciola
// 07 Set 2007 (Worked around MSVC++ bug) Fernando Cacciola, Niels Dekker
// 16 Nov 2007 (Refactoring: removed private base classes) Fernando Cacciola, Niels Dekker
//
#ifndef BOOST_UTILITY_VALUE_INIT_21AGO2002_HPP
#define BOOST_UTILITY_VALUE_INIT_21AGO2002_HPP
@ -14,7 +15,6 @@
#include <boost/type_traits/cv_traits.hpp>
#include <boost/detail/workaround.hpp>
#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1500) )
// Microsoft Visual C++ does not correctly support value initialization, as reported by
// Pavel Kuznetsov (MetaCommunications Engineering), 7/28/2005, Feedback ID 100744,
// Feedback Title: Value-initialization in new-expression
@ -22,10 +22,12 @@
// The report was closed at 11/14/2006, and its status was set to "Closed (Won't Fix)".
// Luckily, even in the presence of this compiler bug, boost::value_initialized will still
// do its job correctly, when using the following workaround:
#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1500))
# define BOOST_UTILITY_VALUE_INIT_WORKAROUND
#endif
#ifdef BOOST_UTILITY_VALUE_INIT_WORKAROUND
#include <boost/aligned_storage.hpp>
#include <boost/type_traits/alignment_of.hpp>
#include <cstring>
@ -43,60 +45,34 @@
namespace boost {
namespace vinit_detail {
template<class T>
class const_T_base
class value_initialized
{
protected :
const_T_base()
{
std::memset(&x, 0, sizeof(x));
new (&x) T();
}
~const_T_base()
{
void const * ptr = &x;
static_cast<T*>(ptr)->T::~T();
}
T & get() const
{
void const * ptr = &x;
return *static_cast<T*>(ptr);
}
private :
typename ::boost::aligned_storage<sizeof(T), ::boost::alignment_of<T>::value>::type x;
} ;
template<class T>
class non_const_T_base
{
protected :
non_const_T_base()
{
std::memset(&x, 0, sizeof(x));
new (&x) T();
}
~non_const_T_base()
{
void * ptr = &x;
static_cast<T*>(ptr)->T::~T();
}
T & get() const
{
void * ptr = &x;
return *static_cast<T*>(ptr);
}
private :
mutable typename ::boost::aligned_storage<sizeof(T), ::boost::alignment_of<T>::value>::type x;
public :
value_initialized()
{
std::memset(&x, 0, sizeof(x));
new (&x) T();
}
~value_initialized()
{
void * ptr = &x;
static_cast<T*>(ptr)->T::~T();
}
T& data() const
{
void * ptr = &x;
return *static_cast<T*>(ptr);
}
operator T&() const { return this->data(); }
} ;
#ifdef BOOST_MSVC
@ -108,59 +84,27 @@ class non_const_T_base
namespace boost {
namespace vinit_detail {
template<class T>
class const_T_base
{
protected :
const_T_base() : x() {}
T & get() const { return x; }
private :
T x ;
} ;
template<class T>
class non_const_T_base
{
protected :
non_const_T_base() : x() {}
T & get() const { return x; }
private :
mutable T x ;
} ;
#endif
template<class T>
struct select_base
{
typedef
#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
typename
#endif
::boost::detail::if_true< ::boost::is_const<T>::value >
::template then< const_T_base<T>, non_const_T_base<T> >::type type ;
} ;
} // namespace vinit_detail
template<class T>
class value_initialized : private vinit_detail::select_base<T>::type
class value_initialized
{
public :
value_initialized() {}
value_initialized() : x() {}
operator T&() const { return this->get(); }
T& data() const { return x; }
T& data() const { return this->get(); }
operator T&() const { return this->data(); }
mutable
#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
typename
#endif
::boost::remove_const<T>::type x ;
} ;
#endif
template<class T>
T const& get ( value_initialized<T> const& x )
@ -177,4 +121,3 @@ T& get ( value_initialized<T>& x )
#endif