mirror/Sprout
1
0
Fork 0
mirror of https://github.com/bolero-MURAKAMI/Sprout.git synced 2025-07-12 14:54:10 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

fix next, prev

Browse source
This commit is contained in:
bolero-MURAKAMI 2012-12-12 17:46:36 +09:00
parent 75228465fe
commit cf9f6670b6
18 changed files with 243 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

54
sprout/iterator/prev.hpp
View file

@ -4,6 +4,8 @@
#include <iterator>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/iterator/next_fwd.hpp>
#include <sprout/iterator/prev_fwd.hpp>
#include <sprout/adl/not_found.hpp>
namespace sprout_adl {
@ -38,8 +40,48 @@ namespace sprout {
{
return it - n;
}
template<typename BidirectionalIterator>
inline SPROUT_CONSTEXPR BidirectionalIterator
prev_impl_1_neg(BidirectionalIterator const& it, typename std::iterator_traits<BidirectionalIterator>::difference_type n) {
return n == -1 ? sprout::next(it)
: sprout::iterator_detail::prev_impl_1_neg(
sprout::iterator_detail::prev_impl_1_neg(it, n / 2),
n - (n / 2)
)
;
}
template<typename BidirectionalIterator>
inline SPROUT_CONSTEXPR BidirectionalIterator
prev_impl_1(BidirectionalIterator const& it, typename std::iterator_traits<BidirectionalIterator>::difference_type n) {
return n == 1 ? sprout::prev(it)
: sprout::iterator_detail::prev_impl_1(
sprout::iterator_detail::prev_impl_1(it, n / 2),
n - (n / 2)
)
;
}
template<typename BidirectionalIterator>
inline SPROUT_CONSTEXPR typename std::enable_if<
std::is_literal_type<BidirectionalIterator>::value,
BidirectionalIterator
>::type
prev_impl(
BidirectionalIterator const& it, typename std::iterator_traits<BidirectionalIterator>::difference_type n,
void*
)
{
return n == 0 ? it
: n > 0 ? sprout::iterator_detail::prev_impl_1(it, n)
: sprout::iterator_detail::prev_impl_1_neg(it, n)
;
}
template<typename BidirectionalIterator>
inline SPROUT_CONSTEXPR typename std::enable_if<
!std::is_literal_type<BidirectionalIterator>::value,
BidirectionalIterator
>::type
prev_impl(
BidirectionalIterator const& it, typename std::iterator_traits<BidirectionalIterator>::difference_type n,
void*
@ -84,11 +126,23 @@ namespace sprout {
//
// prev
//
// effect:
// ADL callable iterator_prev(it) -> iterator_prev(it)
// it is RandomAccessIterator && LiteralType -> it - 1
// otherwise -> std::prev(it)
//
template<typename BidirectionalIterator>
inline SPROUT_CONSTEXPR BidirectionalIterator
prev(BidirectionalIterator const& it) {
return sprout_iterator_detail::prev(it);
}
//
// effect:
// ADL callable iterator_prev(it, n) -> iterator_prev(it, n)
// it is RandomAccessIterator && LiteralType -> it - n
// it is LiteralType -> sprout::prev(it)... || sprout::next(it)...
// otherwise -> std::prev(it, n)
//
template<typename BidirectionalIterator>
inline SPROUT_CONSTEXPR BidirectionalIterator
prev(BidirectionalIterator const& it, typename std::iterator_traits<BidirectionalIterator>::difference_type n) {