gecko-dev/xpcom/ds/nsCppSharedAllocator.h
1999-11-03 07:39:19 +00:00

128 lines
2.5 KiB
C++

#ifndef nsCppSharedAllocator_h__
#define nsCppSharedAllocator_h__
#include "nsIAllocator.h" // for |nsAllocator|
#include "nscore.h" // for |NS_XXX_CAST|
#include <new.h> // to allow placement |new|
// under Metrowerks (Mac), we don't have autoconf yet
#ifdef __MWERKS__
#define HAVE_CPP_MEMBER_TEMPLATES
#define HAVE_CPP_NUMERIC_LIMITS
#endif
// under MSVC shut off copious warnings about unused in-lines
#ifdef _MSC_VER
#pragma warning( disable: 4514 )
#endif
#ifdef HAVE_CPP_NUMERIC_LIMITS
#include <limits>
#else
#include <limits.h>
#endif
template <class T>
class nsCppSharedAllocator
/*
...allows Standard Library containers, et al, to use our global shared
(XP)COM-aware allocator.
*/
{
public:
typedef T value_type;
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef T* pointer;
typedef const T* const_pointer;
typedef T& reference;
typedef const T& const_reference;
nsCppSharedAllocator() { }
#ifdef HAVE_CPP_MEMBER_TEMPLATES
template <class U>
nsCppSharedAllocator( const nsCppSharedAllocator<U>& ) { }
#endif
~nsCppSharedAllocator() { }
pointer
address( reference r ) const
{
return &r;
}
const_pointer
address( const_reference r ) const
{
return &r;
}
pointer
allocate( size_type n, const void* /*hint*/=0 )
{
return NS_REINTERPRET_CAST(pointer, nsAllocator::Alloc(NS_STATIC_CAST(PRUint32, n*sizeof(T))));
}
void
deallocate( pointer p, size_type /*n*/ )
{
nsAllocator::Free(p);
}
void
construct( pointer p, const T& val )
{
new (p) T(val);
}
void
destroy( pointer p )
{
p->~T();
}
size_type
max_size() const
{
#ifdef HAVE_CPP_NUMERIC_LIMITS
return numeric_limits<size_type>::max() / sizeof(T);
#else
return ULONG_MAX / sizeof(T);
#endif
}
#ifdef HAVE_CPP_MEMBER_TEMPLATES
template <class U>
struct rebind
{
typedef nsCppSharedAllocator<U> other;
};
#endif
};
template <class T>
PRBool
operator==( const nsCppSharedAllocator<T>&, const nsCppSharedAllocator<T>& )
{
return PR_TRUE;
}
template <class T>
PRBool
operator!=( const nsCppSharedAllocator<T>&, const nsCppSharedAllocator<T>& )
{
return PR_FALSE;
}
#endif /* !defined(nsCppSharedAllocator_h__) */