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From: Kresimir Fresl (fresl_at_[hidden])
Date: 2001-10-26 06:58:15
Darin Adler wrote:
> The array_traits.hpp predates array.hpp, and is still marked "beta", but I
> love it, use it a lot, and wish it wasn't marked "beta". Maybe I should take
> it through the formal review process.
Sometime ago I added std::valarray<T> support to array_traits.hpp.
It works with gcc and como, but I am not sure that it doesn't violate
standard
valarray `no alias' restrictions.
Maybe this can be useful to someone else.
Sincerely,
fres
// -*-C++-*- array.hpp
// <!!---------------------------------------------------------------------->
// <!! Copyright (C) 1998 Dietmar Kuehl, Claas Solutions GmbH >
// <!!>
// <!! Permission to use, copy, modify, distribute and sell this >
// <!! software for any purpose is hereby granted without fee, provided >
// <!! that the above copyright notice appears in all copies and that >
// <!! both that copyright notice and this permission notice appear in >
// <!! supporting documentation. Dietmar Kuehl and Claas Solutions make no >
// <!! representations about the suitability of this software for any >
// <!! purpose. It is provided "as is" without express or implied warranty. >
// <!!---------------------------------------------------------------------->
// Author: Dietmar Kuehl dietmar.kuehl_at_[hidden]
// Title: STL container support, including support for built-in arrays
// Version: $Id: array_traits.hpp,v 1.3 2001/02/02 20:58:53 jmaurer Exp $
// Dec 4, 2000 Added some more typedefs to array_traits including
// an iterator type to supersede iter_type. -J.Siek
// Feb 23, 2001 Added std::valarray<T> support. --K. F.
// --------------------------------------------------------------------------
#if !defined(BOOST_ARRAY_HPP)
#define BOOST_ARRAY_HPP 1
// --------------------------------------------------------------------------
#include <cstddef>
#include <boost/config.hpp>
#ifndef NO_VALARRAY_SUPPORT
# include <valarray>
#endif
// --------------------------------------------------------------------------
namespace boost
{
// --- a general version of container traits ------------------------------
template <typename Cont>
struct array_traits
{
typedef typename Cont::iterator iterator;
typedef iterator iter_type; // just for backward compatibility
typedef typename Cont::size_type size_type;
typedef typename Cont::value_type value_type;
typedef typename Cont::reference referece;
typedef typename Cont::pointer pointer;
static iterator begin(Cont &cont) { return cont.begin(); }
static iterator end(Cont &cont) { return cont.end(); }
static size_type size(Cont &cont) { return cont.size(); }
};
// --- a version of container traits for constant constainer --------------
template <typename Cont>
struct array_traits<Cont const>
{
typedef typename Cont::const_iterator iterator;
typedef iterator iter_type; // just for backward compatibility
typedef typename Cont::size_type size_type;
typedef typename Cont::value_type value_type;
typedef typename Cont::const_reference reference;
typedef typename Cont::const_pointer pointer;
static iterator begin(Cont const &cont) { return cont.begin(); }
static iterator end(Cont const &cont) { return cont.end(); }
static size_type size(Cont const &cont) { return cont.size(); }
};
// --- a special version for non-const built-in arrays --------------------
template <typename T, std::size_t sz>
struct array_traits<T[sz]>
{
typedef T* iterator;
typedef iterator iter_type; // just for backward compatibility
typedef T value_type;
typedef value_type& reference;
typedef std::size_t size_type;
static iterator begin(T (&array)[sz]) { return array; }
static iterator end(T (&array)[sz]) { return array + sz; }
static size_type size(T (&)[sz]) { return sz; }
};
// --- a special version for const built-in arrays ------------------------
template <typename T, std::size_t sz>
struct array_traits<T const[sz]>
{
typedef T const* iterator;
typedef iterator iter_type; // just for backward compatibility
typedef std::size_t size_type;
typedef T const value_type;
typedef value_type& reference;
typedef value_type* pointer;
static iterator begin(T const (&array)[sz]) { return array; }
static iterator end(T const (&array)[sz]) { return array + sz; }
static size_type size(T const (&array)[sz]) { return sz; }
};
#ifndef NO_VALARRAY_SUPPORT
// --- a special version for non-const valarray<T>s -----------------------
// --K. F.
template <typename T>
struct array_traits< std::valarray<T> >
{
typedef T* iterator;
typedef iterator iter_type; // just for backward compatibility
typedef T value_type;
typedef value_type& reference;
typedef std::size_t size_type;
static iterator begin (std::valarray<T>& va) { return &va[0]; }
static iterator end (std::valarray<T>& va) {
return &va[0] + va.size();
}
static size_type size (std::valarray<T>& va) { return va.size(); }
};
// --- a special version for const valarray<T>s ------------------
// --K. F.
template <typename T>
struct array_traits<std::valarray<T> const>
{
typedef T const* iterator;
typedef iterator iter_type; // just for backward compatibility
typedef std::size_t size_type;
typedef T const value_type;
typedef value_type& reference;
typedef value_type* pointer;
static iterator begin (std::valarray<T> const& cva) {
std::valarray<T>& va = const_cast<std::valarray<T>&> (cva);
return &va[0];
}
static iterator end (std::valarray<T> const& cva) {
std::valarray<T>& va = const_cast<std::valarray<T>&> (cva);
return &va[0] + va.size();
}
static size_type size (std::valarray<T> const& cva) {
return cva.size();
}
};
#endif // NO_VALARRAY_SUPPORT
template <typename T, int sz>
inline char (&sizer(T (&)[sz]))[sz];
// --- general version of the global accessor functions ---------------------
template <typename Cont>
inline typename array_traits<Cont>::iterator
begin(Cont &cont) { return array_traits<Cont>::begin(cont); }
template <typename Cont>
inline typename array_traits<Cont>::iterator
end(Cont &cont) { return array_traits<Cont>::end(cont); }
template <typename Cont>
inline typename array_traits<Cont>::size_type
size(Cont &cont) { return array_traits<Cont>::size(cont); }
// --- Actually the above should be sufficient but compilers seem -----------
// --- to welcome some help. So here we go:
template <typename T, std::size_t sz>
inline typename array_traits<T[sz]>::iterator
begin(T (&a)[sz]) { return array_traits<T[sz]>::begin(a); }
template <typename T, std::size_t sz>
inline typename array_traits<T[sz]>::iterator
end(T (&a)[sz]) { return array_traits<T[sz]>::end(a); }
template <typename T, std::size_t sz>
inline typename array_traits<T[sz]>::size_type
size(T (&a)[sz]) { return array_traits<T[sz]>::size(a); }
// --- Apparently the compilers also need some specific help, ---------------
// --- EDG-2.39 wants to pass around pointers in some contexts --------------
#ifdef __EDG__
template <typename T>
struct array_traits<T*>
{
typedef T* iterator;
typedef iterator iter_type; // just for backward compatibility
typedef std::size_t size_type;
};
#endif
// --- egcs-1998-11-22 apparently likes an extra const version: -------------
#ifdef __GNUG__
template <typename T, std::size_t sz>
inline typename array_traits<T const[sz]>::iterator
begin(T const(&a)[sz]) { return array_traits<T const[sz]>::begin(a); }
template <typename T, std::size_t sz>
inline typename array_traits<T const[sz]>::iterator
end(T const(&a)[sz]) { return array_traits<T const[sz]>::end(a); }
template <typename T, std::size_t sz>
inline typename array_traits<T const[sz]>::size_type
size(T const (&a)[sz]) { return array_traits<T const[sz]>::size(a); }
#endif
}
// -----------------------------------------------------------------------------
#endif /* BOOST_ARRAY_HPP */
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