ecency-mobile/ios/Pods/boost-for-react-native/boost/range/concepts.hpp

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// Boost.Range library concept checks
//
// Copyright Neil Groves 2009. Use, modification and distribution
// are subject to 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)
//
// Copyright Daniel Walker 2006. Use, modification and distribution
// are subject to 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)
//
// For more information, see http://www.boost.org/libs/range/
//
#ifndef BOOST_RANGE_CONCEPTS_HPP
#define BOOST_RANGE_CONCEPTS_HPP
#include <boost/concept_check.hpp>
#include <boost/iterator/iterator_concepts.hpp>
#include <boost/range/begin.hpp>
#include <boost/range/end.hpp>
#include <boost/range/iterator.hpp>
#include <boost/range/value_type.hpp>
#include <boost/range/detail/misc_concept.hpp>
#include <boost/type_traits/remove_reference.hpp>
/*!
* \file
* \brief Concept checks for the Boost Range library.
*
* The structures in this file may be used in conjunction with the
* Boost Concept Check library to insure that the type of a function
* parameter is compatible with a range concept. If not, a meaningful
* compile time error is generated. Checks are provided for the range
* concepts related to iterator traversal categories. For example, the
* following line checks that the type T models the ForwardRange
* concept.
*
* \code
* BOOST_CONCEPT_ASSERT((ForwardRangeConcept<T>));
* \endcode
*
* A different concept check is required to ensure writeable value
* access. For example to check for a ForwardRange that can be written
* to, the following code is required.
*
* \code
* BOOST_CONCEPT_ASSERT((WriteableForwardRangeConcept<T>));
* \endcode
*
* \see http://www.boost.org/libs/range/doc/range.html for details
* about range concepts.
* \see http://www.boost.org/libs/iterator/doc/iterator_concepts.html
* for details about iterator concepts.
* \see http://www.boost.org/libs/concept_check/concept_check.htm for
* details about concept checks.
*/
namespace boost {
namespace range_detail {
#ifndef BOOST_RANGE_ENABLE_CONCEPT_ASSERT
// List broken compiler versions here:
#ifndef __clang__
#ifdef __GNUC__
// GNUC 4.2 has strange issues correctly detecting compliance with the Concepts
// hence the least disruptive approach is to turn-off the concept checking for
// this version of the compiler.
#if __GNUC__ == 4 && __GNUC_MINOR__ == 2
#define BOOST_RANGE_ENABLE_CONCEPT_ASSERT 0
#endif
#endif
#ifdef __GCCXML__
// GCC XML, unsurprisingly, has the same issues
#if __GCCXML_GNUC__ == 4 && __GCCXML_GNUC_MINOR__ == 2
#define BOOST_RANGE_ENABLE_CONCEPT_ASSERT 0
#endif
#endif
#endif
#ifdef __BORLANDC__
#define BOOST_RANGE_ENABLE_CONCEPT_ASSERT 0
#endif
#ifdef __PATHCC__
#define BOOST_RANGE_ENABLE_CONCEPT_ASSERT 0
#endif
// Default to using the concept asserts unless we have defined it off
// during the search for black listed compilers.
#ifndef BOOST_RANGE_ENABLE_CONCEPT_ASSERT
#define BOOST_RANGE_ENABLE_CONCEPT_ASSERT 1
#endif
#endif
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
#define BOOST_RANGE_CONCEPT_ASSERT( x ) BOOST_CONCEPT_ASSERT( x )
#else
#define BOOST_RANGE_CONCEPT_ASSERT( x )
#endif
// Rationale for the inclusion of redefined iterator concept
// classes:
//
// The Range algorithms often do not require that the iterators are
// Assignable or default constructable, but the correct standard
// conformant iterators do require the iterators to be a model of the
// Assignable concept.
// Iterators that contains a functor that is not assignable therefore
// are not correct models of the standard iterator concepts,
// despite being adequate for most algorithms. An example of this
// use case is the combination of the boost::adaptors::filtered
// class with a boost::lambda::bind generated functor.
// Ultimately modeling the range concepts using composition
// with the Boost.Iterator concepts would render the library
// incompatible with many common Boost.Lambda expressions.
template<class Iterator>
struct IncrementableIteratorConcept : CopyConstructible<Iterator>
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
typedef BOOST_DEDUCED_TYPENAME iterator_traversal<Iterator>::type traversal_category;
BOOST_RANGE_CONCEPT_ASSERT((
Convertible<
traversal_category,
incrementable_traversal_tag
>));
BOOST_CONCEPT_USAGE(IncrementableIteratorConcept)
{
++i;
(void)i++;
}
private:
Iterator i;
#endif
};
template<class Iterator>
struct SinglePassIteratorConcept
: IncrementableIteratorConcept<Iterator>
, EqualityComparable<Iterator>
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
BOOST_RANGE_CONCEPT_ASSERT((
Convertible<
BOOST_DEDUCED_TYPENAME SinglePassIteratorConcept::traversal_category,
single_pass_traversal_tag
>));
BOOST_CONCEPT_USAGE(SinglePassIteratorConcept)
{
Iterator i2(++i);
boost::ignore_unused_variable_warning(i2);
// deliberately we are loose with the postfix version for the single pass
// iterator due to the commonly poor adherence to the specification means that
// many algorithms would be unusable, whereas actually without the check they
// work
(void)(i++);
BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<Iterator>::reference r1(*i);
boost::ignore_unused_variable_warning(r1);
BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<Iterator>::reference r2(*(++i));
boost::ignore_unused_variable_warning(r2);
}
private:
Iterator i;
#endif
};
template<class Iterator>
struct ForwardIteratorConcept
: SinglePassIteratorConcept<Iterator>
, DefaultConstructible<Iterator>
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
typedef BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<Iterator>::difference_type difference_type;
BOOST_MPL_ASSERT((is_integral<difference_type>));
BOOST_MPL_ASSERT_RELATION(std::numeric_limits<difference_type>::is_signed, ==, true);
BOOST_RANGE_CONCEPT_ASSERT((
Convertible<
BOOST_DEDUCED_TYPENAME ForwardIteratorConcept::traversal_category,
forward_traversal_tag
>));
BOOST_CONCEPT_USAGE(ForwardIteratorConcept)
{
// See the above note in the SinglePassIteratorConcept about the handling of the
// postfix increment. Since with forward and better iterators there is no need
// for a proxy, we can sensibly require that the dereference result
// is convertible to reference.
Iterator i2(i++);
boost::ignore_unused_variable_warning(i2);
BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<Iterator>::reference r(*(i++));
boost::ignore_unused_variable_warning(r);
}
private:
Iterator i;
#endif
};
template<class Iterator>
struct BidirectionalIteratorConcept
: ForwardIteratorConcept<Iterator>
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
BOOST_RANGE_CONCEPT_ASSERT((
Convertible<
BOOST_DEDUCED_TYPENAME BidirectionalIteratorConcept::traversal_category,
bidirectional_traversal_tag
>));
BOOST_CONCEPT_USAGE(BidirectionalIteratorConcept)
{
--i;
(void)i--;
}
private:
Iterator i;
#endif
};
template<class Iterator>
struct RandomAccessIteratorConcept
: BidirectionalIteratorConcept<Iterator>
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
BOOST_RANGE_CONCEPT_ASSERT((
Convertible<
BOOST_DEDUCED_TYPENAME RandomAccessIteratorConcept::traversal_category,
random_access_traversal_tag
>));
BOOST_CONCEPT_USAGE(RandomAccessIteratorConcept)
{
i += n;
i = i + n;
i = n + i;
i -= n;
i = i - n;
n = i - j;
}
private:
BOOST_DEDUCED_TYPENAME RandomAccessIteratorConcept::difference_type n;
Iterator i;
Iterator j;
#endif
};
} // namespace range_detail
//! Check if a type T models the SinglePassRange range concept.
template<class T>
struct SinglePassRangeConcept
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
// A few compilers don't like the rvalue reference T types so just
// remove it.
typedef BOOST_DEDUCED_TYPENAME remove_reference<T>::type Rng;
typedef BOOST_DEDUCED_TYPENAME range_iterator<
Rng const
>::type const_iterator;
typedef BOOST_DEDUCED_TYPENAME range_iterator<Rng>::type iterator;
BOOST_RANGE_CONCEPT_ASSERT((
range_detail::SinglePassIteratorConcept<iterator>));
BOOST_RANGE_CONCEPT_ASSERT((
range_detail::SinglePassIteratorConcept<const_iterator>));
BOOST_CONCEPT_USAGE(SinglePassRangeConcept)
{
// This has been modified from assigning to this->i
// (where i was a member variable) to improve
// compatibility with Boost.Lambda
iterator i1 = boost::begin(*m_range);
iterator i2 = boost::end(*m_range);
boost::ignore_unused_variable_warning(i1);
boost::ignore_unused_variable_warning(i2);
const_constraints(*m_range);
}
private:
void const_constraints(const Rng& const_range)
{
const_iterator ci1 = boost::begin(const_range);
const_iterator ci2 = boost::end(const_range);
boost::ignore_unused_variable_warning(ci1);
boost::ignore_unused_variable_warning(ci2);
}
// Rationale:
// The type of m_range is T* rather than T because it allows
// T to be an abstract class. The other obvious alternative of
// T& produces a warning on some compilers.
Rng* m_range;
#endif
};
//! Check if a type T models the ForwardRange range concept.
template<class T>
struct ForwardRangeConcept : SinglePassRangeConcept<T>
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
BOOST_RANGE_CONCEPT_ASSERT((range_detail::ForwardIteratorConcept<BOOST_DEDUCED_TYPENAME ForwardRangeConcept::iterator>));
BOOST_RANGE_CONCEPT_ASSERT((range_detail::ForwardIteratorConcept<BOOST_DEDUCED_TYPENAME ForwardRangeConcept::const_iterator>));
#endif
};
template<class T>
struct WriteableRangeConcept
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
typedef BOOST_DEDUCED_TYPENAME range_iterator<T>::type iterator;
BOOST_CONCEPT_USAGE(WriteableRangeConcept)
{
*i = v;
}
private:
iterator i;
BOOST_DEDUCED_TYPENAME range_value<T>::type v;
#endif
};
//! Check if a type T models the WriteableForwardRange range concept.
template<class T>
struct WriteableForwardRangeConcept
: ForwardRangeConcept<T>
, WriteableRangeConcept<T>
{
};
//! Check if a type T models the BidirectionalRange range concept.
template<class T>
struct BidirectionalRangeConcept : ForwardRangeConcept<T>
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
BOOST_RANGE_CONCEPT_ASSERT((range_detail::BidirectionalIteratorConcept<BOOST_DEDUCED_TYPENAME BidirectionalRangeConcept::iterator>));
BOOST_RANGE_CONCEPT_ASSERT((range_detail::BidirectionalIteratorConcept<BOOST_DEDUCED_TYPENAME BidirectionalRangeConcept::const_iterator>));
#endif
};
//! Check if a type T models the WriteableBidirectionalRange range concept.
template<class T>
struct WriteableBidirectionalRangeConcept
: BidirectionalRangeConcept<T>
, WriteableRangeConcept<T>
{
};
//! Check if a type T models the RandomAccessRange range concept.
template<class T>
struct RandomAccessRangeConcept : BidirectionalRangeConcept<T>
{
#if BOOST_RANGE_ENABLE_CONCEPT_ASSERT
BOOST_RANGE_CONCEPT_ASSERT((range_detail::RandomAccessIteratorConcept<BOOST_DEDUCED_TYPENAME RandomAccessRangeConcept::iterator>));
BOOST_RANGE_CONCEPT_ASSERT((range_detail::RandomAccessIteratorConcept<BOOST_DEDUCED_TYPENAME RandomAccessRangeConcept::const_iterator>));
#endif
};
//! Check if a type T models the WriteableRandomAccessRange range concept.
template<class T>
struct WriteableRandomAccessRangeConcept
: RandomAccessRangeConcept<T>
, WriteableRangeConcept<T>
{
};
} // namespace boost
#endif // BOOST_RANGE_CONCEPTS_HPP