forked from boostorg/iterator
85 lines
2.4 KiB
C++
85 lines
2.4 KiB
C++
// (C) Copyright David Abrahams 2002.
|
|
// (C) Copyright Jeremy Siek 2002.
|
|
// (C) Copyright Thomas Witt 2002.
|
|
// Distributed under the Boost Software License, Version 1.0. (See
|
|
// accompanying file LICENSE_1_0.txt or copy at
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
|
|
|
// no include guard multiple inclusion intended
|
|
|
|
//
|
|
// This is a temporary workaround until the bulk of this is
|
|
// available in boost config.
|
|
// 23/02/03 thw
|
|
//
|
|
|
|
#include <boost/config.hpp> // for prior
|
|
#include <boost/detail/workaround.hpp>
|
|
|
|
#ifdef BOOST_ITERATOR_CONFIG_DEF
|
|
# error you have nested config_def #inclusion.
|
|
#else
|
|
# define BOOST_ITERATOR_CONFIG_DEF
|
|
#endif
|
|
|
|
// We enable this always now. Otherwise, the simple case in
|
|
// libs/iterator/test/constant_iterator_arrow.cpp fails to compile
|
|
// because the operator-> return is improperly deduced as a non-const
|
|
// pointer.
|
|
#if 1 || defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \
|
|
|| BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x531))
|
|
|
|
// Recall that in general, compilers without partial specialization
|
|
// can't strip constness. Consider counting_iterator, which normally
|
|
// passes a const Value to iterator_facade. As a result, any code
|
|
// which makes a std::vector of the iterator's value_type will fail
|
|
// when its allocator declares functions overloaded on reference and
|
|
// const_reference (the same type).
|
|
//
|
|
// Furthermore, Borland 5.5.1 drops constness in enough ways that we
|
|
// end up using a proxy for operator[] when we otherwise shouldn't.
|
|
// Using reference constness gives it an extra hint that it can
|
|
// return the value_type from operator[] directly, but is not
|
|
// strictly necessary. Not sure how best to resolve this one.
|
|
|
|
# define BOOST_ITERATOR_REF_CONSTNESS_KILLS_WRITABILITY 1
|
|
|
|
#endif
|
|
|
|
#if (BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, <= 700) && defined(_MSC_VER)) \
|
|
|| BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590))
|
|
|
|
# define BOOST_NO_LVALUE_RETURN_DETECTION
|
|
|
|
# if 0 // test code
|
|
struct v {};
|
|
|
|
typedef char (&no)[3];
|
|
|
|
template <class T>
|
|
no foo(T const&, ...);
|
|
|
|
template <class T>
|
|
char foo(T&, int);
|
|
|
|
|
|
struct value_iterator
|
|
{
|
|
v operator*() const;
|
|
};
|
|
|
|
template <class T>
|
|
struct lvalue_deref_helper
|
|
{
|
|
static T& x;
|
|
enum { value = (sizeof(foo(*x,0)) == 1) };
|
|
};
|
|
|
|
int z2[(lvalue_deref_helper<v*>::value == 1) ? 1 : -1];
|
|
int z[(lvalue_deref_helper<value_iterator>::value) == 1 ? -1 : 1 ];
|
|
# endif
|
|
|
|
#endif
|
|
|
|
// no include guard; multiple inclusion intended
|