118 lines
4.4 KiB
C++
118 lines
4.4 KiB
C++
// Copyright (c) 2009-2020 Vladimir Batov.
|
|
// Use, modification and distribution are subject to the Boost Software License,
|
|
// Version 1.0. See http://www.boost.org/LICENSE_1_0.txt.
|
|
|
|
#ifndef BOOST_CONVERT_DETAIL_RANGE_HPP
|
|
#define BOOST_CONVERT_DETAIL_RANGE_HPP
|
|
|
|
#include <boost/convert/detail/has_member.hpp>
|
|
#include <boost/convert/detail/char.hpp>
|
|
#include <boost/range/iterator.hpp>
|
|
|
|
namespace boost::cnv
|
|
{
|
|
namespace detail
|
|
{
|
|
template<typename T, bool is_class> struct is_range : std::false_type {};
|
|
|
|
template<typename T> struct is_range<T, /*is_class=*/true>
|
|
{
|
|
BOOST_DECLARE_HAS_MEMBER(has_begin, begin);
|
|
BOOST_DECLARE_HAS_MEMBER( has_end, end);
|
|
|
|
static bool BOOST_CONSTEXPR_OR_CONST value = has_begin<T>::value && has_end<T>::value;
|
|
};
|
|
}
|
|
template<typename T> struct is_range : detail::is_range<typename boost::remove_const<T>::type, boost::is_class<T>::value> {};
|
|
template<typename T, typename enable =void> struct range;
|
|
template<typename T, typename enable =void> struct iterator;
|
|
|
|
template<typename T>
|
|
struct iterator<T, typename std::enable_if<is_range<T>::value>::type>
|
|
{
|
|
using type = typename boost::range_iterator<T>::type;
|
|
using const_type = typename boost::range_iterator<T const>::type;
|
|
using value_type = typename boost::iterator_value<type>::type;
|
|
};
|
|
template<typename T>
|
|
struct iterator<T*, void>
|
|
{
|
|
using value_type = typename boost::remove_const<T>::type;
|
|
using type = T*;
|
|
using const_type = value_type const*;
|
|
};
|
|
template<typename T>
|
|
struct range_base
|
|
{
|
|
using value_type = typename cnv::iterator<T>::value_type;
|
|
using iterator = typename cnv::iterator<T>::type;
|
|
using const_iterator = typename cnv::iterator<T>::const_type;
|
|
using sentry_type = const_iterator;
|
|
|
|
iterator begin () { return begin_; }
|
|
const_iterator begin () const { return begin_; }
|
|
void operator++ () { ++begin_; }
|
|
// void operator-- () { --end_; }
|
|
|
|
protected:
|
|
|
|
range_base (iterator b, iterator e) : begin_(b), end_(e) {}
|
|
|
|
iterator begin_;
|
|
iterator mutable end_;
|
|
};
|
|
|
|
template<typename T>
|
|
struct range<T, typename std::enable_if<is_range<T>::value>::type> : public range_base<T>
|
|
{
|
|
using this_type = range;
|
|
using base_type = range_base<T>;
|
|
using iterator = typename base_type::iterator;
|
|
using const_iterator = typename base_type::const_iterator;
|
|
using sentry_type = const_iterator;
|
|
|
|
range (T& r) : base_type(r.begin(), r.end()) {}
|
|
|
|
iterator end () { return base_type::end_; }
|
|
const_iterator end () const { return base_type::end_; }
|
|
sentry_type sentry () const { return base_type::end_; }
|
|
std::size_t size () const { return base_type::end_ - base_type::begin_; }
|
|
bool empty () const { return base_type::begin_ == base_type::end_; }
|
|
};
|
|
|
|
template<typename T>
|
|
struct range<T*, typename std::enable_if<cnv::is_char<T>::value>::type> : public range_base<T*>
|
|
{
|
|
using this_type = range;
|
|
using base_type = range_base<T*>;
|
|
using value_type = typename boost::remove_const<T>::type;
|
|
using iterator = T*;
|
|
using const_iterator = value_type const*;
|
|
|
|
struct sentry_type
|
|
{
|
|
friend bool operator!=(iterator it, sentry_type) { return !!*it; }
|
|
};
|
|
|
|
range (iterator b, iterator e =0) : base_type(b, e) {}
|
|
|
|
iterator end () { return base_type::end_ ? base_type::end_ : (base_type::end_ = base_type::begin_ + size()); }
|
|
const_iterator end () const { return base_type::end_ ? base_type::end_ : (base_type::end_ = base_type::begin_ + size()); }
|
|
sentry_type sentry () const { return sentry_type(); }
|
|
std::size_t size () const { return std::char_traits<value_type>::length(base_type::begin_); }
|
|
bool empty () const { return !*base_type::begin_; }
|
|
};
|
|
template<typename T>
|
|
struct range<T* const, void> : public range<T*>
|
|
{
|
|
range (T* b, T* e =0) : range<T*>(b, e) {}
|
|
};
|
|
template <typename T, std::size_t N>
|
|
struct range<T [N], void> : public range<T*>
|
|
{
|
|
range (T* b, T* e =0) : range<T*>(b, e) {}
|
|
};
|
|
}
|
|
|
|
#endif // BOOST_CONVERT_DETAIL_RANGE_HPP
|