King_DuckZ/Sprout
1
0
Fork 0
mirror of https://github.com/bolero-MURAKAMI/Sprout synced 2025-08-03 12:49:50 +00:00
Code Issues Releases Wiki Activity

fix adaptors alternated, taken, dropped, etc...

Browse source
This commit is contained in:
bolero-MURAKAMI 2012-12-01 03:00:46 +09:00
parent 84e3348402
commit 86818d73cb
16 changed files with 207 additions and 157 deletions
Download patch file Download diff file Expand all files Collapse all files

39
sprout/range/adaptor/copied.hpp
View file

@ -7,7 +7,7 @@
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/algorithm/fixed/result_of.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/adaptor/detail/adapted_range_default.hpp>
#include <sprout/range/algorithm/copy.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/utility/forward.hpp>
@ -21,17 +21,11 @@ namespace sprout {
//
template<typename Range>
class copied_range
: public sprout::range::range_container<
typename sprout::container_traits<Range>::iterator
>
, public sprout::detail::container_nosy_static_size<Range>
, public sprout::detail::container_nosy_fixed_size<Range>
: public sprout::adaptors::detail::adapted_range_default<Range>
{
public:
typedef Range range_type;
typedef sprout::range::range_container<
typename sprout::container_traits<Range>::iterator
> base_type;
typedef sprout::adaptors::detail::adapted_range_default<Range> base_type;
typedef typename base_type::range_type range_type;
public:
copied_range() = default;
copied_range(copied_range const&) = default;
@ -111,28 +105,9 @@ namespace sprout {
// container_construct_traits
//
template<typename Range>
struct container_construct_traits<sprout::adaptors::copied_range<Range> > {
public:
typedef typename sprout::container_construct_traits<Range>::copied_type copied_type;
public:
template<typename Cont>
static SPROUT_CONSTEXPR copied_type deep_copy(Cont&& cont) {
return sprout::range::fixed::copy(sprout::forward<Cont>(cont), sprout::pit<copied_type>());
}
template<typename... Args>
static SPROUT_CONSTEXPR copied_type make(Args&&... args) {
return sprout::make<copied_type>(sprout::forward<Args>(args)...);
}
template<typename Cont, typename... Args>
static SPROUT_CONSTEXPR copied_type remake(
Cont&& cont,
typename sprout::container_traits<sprout::adaptors::copied_range<Range> >::difference_type size,
Args&&... args
)
{
return sprout::remake<copied_type>(sprout::forward<Cont>(cont), size, sprout::forward<Args>(args)...);
}
};
struct container_construct_traits<sprout::adaptors::copied_range<Range> >
: public sprout::container_construct_traits<typename sprout::adaptors::copied_range<Range>::base_type>
{};
} // namespace sprout
#endif // #ifndef SPROUT_RANGE_ADAPTOR_COPIED_HPP

63
sprout/range/adaptor/detail/adapted_range_default.hpp Normal file
View file

@ -0,0 +1,63 @@
#ifndef SPROUT_RANGE_ADAPTOR_DETAIL_ADAPTED_RANGE_DEFAULT_HPP
#define SPROUT_RANGE_ADAPTOR_DETAIL_ADAPTED_RANGE_DEFAULT_HPP
#include <sprout/config.hpp>
#include <sprout/pit.hpp>
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/algorithm/copy.hpp>
#include <sprout/utility/forward.hpp>
namespace sprout {
namespace adaptors {
namespace detail {
template<typename Range, typename Iterator = typename sprout::container_traits<Range>::iterator>
class adapted_range_default
: public sprout::range::range_container<Iterator>
, public sprout::detail::container_nosy_static_size<Range>
, public sprout::detail::container_nosy_fixed_size<Range>
{
public:
typedef Range range_type;
typedef sprout::range::range_container<Iterator> base_type;
typedef typename base_type::iterator iterator;
public:
adapted_range_default() = default;
adapted_range_default(adapted_range_default const&) = default;
explicit SPROUT_CONSTEXPR adapted_range_default(iterator const& first, iterator const& last)
: base_type(first, last)
{}
};
} // namespace detail
} // namespace adaptors
//
// container_construct_traits
//
template<typename Range, typename Iterator>
struct container_construct_traits<sprout::adaptors::detail::adapted_range_default<Range, Iterator> > {
public:
typedef typename sprout::container_construct_traits<Range>::copied_type copied_type;
public:
template<typename Cont>
static SPROUT_CONSTEXPR copied_type deep_copy(Cont&& cont) {
return sprout::range::fixed::copy(sprout::forward<Cont>(cont), sprout::pit<copied_type>());
}
template<typename... Args>
static SPROUT_CONSTEXPR copied_type make(Args&&... args) {
return sprout::make<copied_type>(sprout::forward<Args>(args)...);
}
template<typename Cont, typename... Args>
static SPROUT_CONSTEXPR copied_type remake(
Cont&& cont,
typename sprout::container_traits<sprout::adaptors::detail::adapted_range_default<Range> >::difference_type size,
Args&&... args
)
{
return sprout::remake<copied_type>(sprout::forward<Cont>(cont), size, sprout::forward<Args>(args)...);
}
};
} // namespace sprout
#endif // #ifndef SPROUT_RANGE_ADAPTOR_DETAIL_ADAPTED_RANGE_DEFAULT_HPP

10
sprout/range/adaptor/dropped.hpp
View file

@ -6,7 +6,7 @@
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/next.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/adaptor/detail/adapted_range_default.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/utility/lvalue_forward.hpp>
#include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
@ -54,15 +54,15 @@ namespace sprout {
// operator|
//
template<typename Range, typename Difference>
inline SPROUT_CONSTEXPR sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
inline SPROUT_CONSTEXPR sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>
operator|(Range&& lhs, sprout::adaptors::drop_holder<Difference> const& rhs) {
typedef typename sprout::container_traits<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>::difference_type difference_type;
return sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
return sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>(
sprout::next(
sprout::begin(sprout::lvalue_forward<Range>(lhs)),

10
sprout/range/adaptor/dropped_end.hpp
View file

@ -6,7 +6,7 @@
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/next.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/adaptor/detail/adapted_range_default.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/utility/lvalue_forward.hpp>
#include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
@ -54,15 +54,15 @@ namespace sprout {
// operator|
//
template<typename Range, typename Difference>
inline SPROUT_CONSTEXPR sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
inline SPROUT_CONSTEXPR sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>
operator|(Range&& lhs, sprout::adaptors::drop_end_holder<Difference> const& rhs) {
typedef typename sprout::container_traits<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>::difference_type difference_type;
return sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
return sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>(
sprout::begin(sprout::lvalue_forward<Range>(lhs)),
sprout::next(

20
sprout/range/adaptor/offset.hpp
View file

@ -6,7 +6,7 @@
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/next.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/adaptor/detail/adapted_range_default.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/type_traits/arithmetic_promote.hpp>
#include <sprout/utility/lvalue_forward.hpp>
@ -78,16 +78,16 @@ namespace sprout {
// operator|
//
template<typename Range, typename Difference1, typename Difference2>
inline SPROUT_CONSTEXPR sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
inline SPROUT_CONSTEXPR sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>
operator|(Range&& lhs, sprout::adaptors::offset_holder<Difference1, Difference2> const& rhs) {
typedef typename sprout::container_traits<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>::difference_type difference_type;
return sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
>(
return sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>(
sprout::next(
sprout::begin(sprout::lvalue_forward<Range>(lhs)),
NS_SSCRISK_CEL_OR_SPROUT::min<difference_type>(rhs.from_begin(), sprout::size(sprout::lvalue_forward<Range>(lhs)))
@ -102,15 +102,15 @@ namespace sprout {
);
}
template<typename Range, typename Difference>
inline SPROUT_CONSTEXPR sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
inline SPROUT_CONSTEXPR sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>
operator|(Range&& lhs, sprout::adaptors::offset_holder<Difference> const& rhs) {
typedef typename sprout::container_traits<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>::difference_type difference_type;
return sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
return sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>(
sprout::next(
sprout::begin(sprout::lvalue_forward<Range>(lhs)),

45
sprout/range/adaptor/reversed.hpp
View file

@ -7,7 +7,7 @@
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/reverse_iterator.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/adaptor/detail/adapted_range_default.hpp>
#include <sprout/range/algorithm/copy.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/utility/forward.hpp>
@ -20,21 +20,17 @@ namespace sprout {
//
template<typename Range>
class reversed_range
: public sprout::range::range_container<
sprout::reverse_iterator<
typename sprout::container_traits<Range>::iterator
>
: public sprout::adaptors::detail::adapted_range_default<
Range,
sprout::reverse_iterator<typename sprout::container_traits<Range>::iterator>
>
, public sprout::detail::container_nosy_static_size<Range>
, public sprout::detail::container_nosy_fixed_size<Range>
{
public:
typedef Range range_type;
typedef sprout::range::range_container<
sprout::reverse_iterator<
typename sprout::container_traits<Range>::iterator
>
typedef sprout::adaptors::detail::adapted_range_default<
Range,
sprout::reverse_iterator<typename sprout::container_traits<Range>::iterator>
> base_type;
typedef typename base_type::range_type range_type;
typedef typename base_type::iterator iterator;
public:
reversed_range() = default;
@ -79,28 +75,9 @@ namespace sprout {
// container_construct_traits
//
template<typename Range>
struct container_construct_traits<sprout::adaptors::reversed_range<Range> > {
public:
typedef typename sprout::container_construct_traits<Range>::copied_type copied_type;
public:
template<typename Cont>
static SPROUT_CONSTEXPR copied_type deep_copy(Cont&& cont) {
return sprout::range::fixed::copy(sprout::forward<Cont>(cont), sprout::pit<copied_type>());
}
template<typename... Args>
static SPROUT_CONSTEXPR copied_type make(Args&&... args) {
return sprout::make<copied_type>(sprout::forward<Args>(args)...);
}
template<typename Cont, typename... Args>
static SPROUT_CONSTEXPR copied_type remake(
Cont&& cont,
typename sprout::container_traits<sprout::adaptors::reversed_range<Range> >::difference_type size,
Args&&... args
)
{
return sprout::remake<copied_type>(sprout::forward<Cont>(cont), size, sprout::forward<Args>(args)...);
}
};
struct container_construct_traits<sprout::adaptors::reversed_range<Range> >
: public sprout::container_construct_traits<typename sprout::adaptors::reversed_range<Range>::base_type>
{};
} // namespace sprout
#endif // #ifndef SPROUT_RANGE_ADAPTOR_REVERSED_HPP

10
sprout/range/adaptor/taken.hpp
View file

@ -6,7 +6,7 @@
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/next.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/adaptor/detail/adapted_range_default.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/utility/lvalue_forward.hpp>
#include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
@ -54,15 +54,15 @@ namespace sprout {
// operator|
//
template<typename Range, typename Difference>
inline SPROUT_CONSTEXPR sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
inline SPROUT_CONSTEXPR sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>
operator|(Range&& lhs, sprout::adaptors::take_holder<Difference> const& rhs) {
typedef typename sprout::container_traits<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>::difference_type difference_type;
return sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
return sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>(
sprout::begin(sprout::lvalue_forward<Range>(lhs)),
sprout::next(

10
sprout/range/adaptor/taken_end.hpp
View file

@ -6,7 +6,7 @@
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/next.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/adaptor/detail/adapted_range_default.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/utility/lvalue_forward.hpp>
#include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
@ -54,15 +54,15 @@ namespace sprout {
// operator|
//
template<typename Range, typename Difference>
inline SPROUT_CONSTEXPR sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
inline SPROUT_CONSTEXPR sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>
operator|(Range&& lhs, sprout::adaptors::take_end_holder<Difference> const& rhs) {
typedef typename sprout::container_traits<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>::difference_type difference_type;
return sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
return sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>(
sprout::next(
sprout::end(sprout::lvalue_forward<Range>(lhs)),

52
sprout/range/adaptor/transformed.hpp
View file

@ -7,7 +7,7 @@
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/transform_iterator.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/adaptor/detail/adapted_range_default.hpp>
#include <sprout/range/algorithm/copy.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/utility/forward.hpp>
@ -21,21 +21,21 @@ namespace sprout {
//
template<typename BinaryFunction, typename LRange, typename RRange = void>
class transformed_range
: public sprout::range::range_container<
: public sprout::adaptors::detail::adapted_range_default<
LRange,
sprout::transform_iterator<
BinaryFunction,
typename sprout::container_traits<LRange>::iterator,
typename sprout::container_traits<RRange>::iterator
>
>
, public sprout::detail::container_nosy_static_size<LRange>
, public sprout::detail::container_nosy_fixed_size<LRange>
{
public:
typedef BinaryFunction functor_type;
typedef LRange range_type;
typedef LRange range1_type;
typedef RRange range2_type;
typedef sprout::range::range_container<
typedef sprout::adaptors::detail::adapted_range_default<
LRange,
sprout::transform_iterator<
BinaryFunction,
typename sprout::container_traits<LRange>::iterator,
@ -43,11 +43,10 @@ namespace sprout {
>
> base_type;
typedef typename base_type::iterator iterator;
typedef typename base_type::size_type size_type;
public:
transformed_range() = default;
transformed_range(transformed_range const&) = default;
SPROUT_CONSTEXPR transformed_range(functor_type func, range_type& range1, range2_type& range2)
SPROUT_CONSTEXPR transformed_range(functor_type func, range1_type& range1, range2_type& range2)
: base_type(
iterator(sprout::begin(range1), sprout::begin(range2), func),
iterator(sprout::end(range1), sprout::end(range2), func)
@ -57,19 +56,19 @@ namespace sprout {
template<typename UnaryFunction, typename Range>
class transformed_range<UnaryFunction, Range, void>
: public sprout::range::range_container<
: public sprout::adaptors::detail::adapted_range_default<
Range,
sprout::transform_iterator<
UnaryFunction,
typename sprout::container_traits<Range>::iterator
>
>
, public sprout::detail::container_nosy_static_size<Range>
, public sprout::detail::container_nosy_fixed_size<Range>
{
public:
typedef UnaryFunction functor_type;
typedef Range range_type;
typedef sprout::range::range_container<
typedef Range range1_type;
typedef sprout::adaptors::detail::adapted_range_default<
Range,
sprout::transform_iterator<
UnaryFunction,
typename sprout::container_traits<Range>::iterator
@ -79,7 +78,7 @@ namespace sprout {
public:
transformed_range() = default;
transformed_range(transformed_range const&) = default;
SPROUT_CONSTEXPR transformed_range(functor_type func, range_type& range)
SPROUT_CONSTEXPR transformed_range(functor_type func, range1_type& range)
: base_type(
iterator(sprout::begin(range), func),
iterator(sprout::end(range), func)
@ -202,28 +201,9 @@ namespace sprout {
// container_construct_traits
//
template<typename UnaryOrBinaryFunction, typename LRange, typename RRange>
struct container_construct_traits<sprout::adaptors::transformed_range<UnaryOrBinaryFunction, LRange, RRange> > {
public:
typedef typename sprout::container_construct_traits<LRange>::copied_type copied_type;
public:
template<typename Cont>
static SPROUT_CONSTEXPR copied_type deep_copy(Cont&& cont) {
return sprout::range::fixed::copy(sprout::forward<Cont>(cont), sprout::pit<copied_type>());
}
template<typename... Args>
static SPROUT_CONSTEXPR copied_type make(Args&&... args) {
return sprout::make<copied_type>(sprout::forward<Args>(args)...);
}
template<typename Cont, typename... Args>
static SPROUT_CONSTEXPR copied_type remake(
Cont&& cont,
typename sprout::container_traits<sprout::adaptors::transformed_range<UnaryOrBinaryFunction, LRange, RRange> >::difference_type size,
Args&&... args
)
{
return sprout::remake<copied_type>(sprout::forward<Cont>(cont), size, sprout::forward<Args>(args)...);
}
};
struct container_construct_traits<sprout::adaptors::transformed_range<UnaryOrBinaryFunction, LRange, RRange> >
: public sprout::container_construct_traits<typename sprout::adaptors::transformed_range<UnaryOrBinaryFunction, LRange, RRange>::base_type>
{};
} // namespace sprout
#endif // #ifndef SPROUT_RANGE_ADAPTOR_TRANSFORMD_HPP

18
sprout/range/adaptor/window.hpp
View file

@ -6,7 +6,7 @@
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/next.hpp>
#include <sprout/range/range_container.hpp>
#include <sprout/range/adaptor/detail/adapted_range_default.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/type_traits/arithmetic_promote.hpp>
#include <sprout/utility/lvalue_forward.hpp>
@ -78,15 +78,15 @@ namespace sprout {
// operator|
//
template<typename Range, typename Difference1, typename Difference2>
inline SPROUT_CONSTEXPR sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
inline SPROUT_CONSTEXPR sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>
operator|(Range&& lhs, sprout::adaptors::window_holder<Difference1, Difference2> const& rhs) {
typedef typename sprout::container_traits<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>::difference_type difference_type;
return sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
return sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>(
sprout::next(
sprout::begin(sprout::lvalue_forward<Range>(lhs)),
@ -99,15 +99,15 @@ namespace sprout {
);
}
template<typename Range, typename Difference>
inline SPROUT_CONSTEXPR sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
inline SPROUT_CONSTEXPR sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>
operator|(Range&& lhs, sprout::adaptors::window_holder<Difference> const& rhs) {
typedef typename sprout::container_traits<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>::difference_type difference_type;
return sprout::range::range_container<
typename sprout::container_traits<typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type>::iterator
return sprout::adaptors::detail::adapted_range_default<
typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
>(
sprout::next(
sprout::begin(sprout::lvalue_forward<Range>(lhs)),