I find it easier to work with this class when the declarations match the
order in the C++2a working paper.
There's no need to use long, descriptive template parameter names like
_ContiguousIterator when the parameter is already constrained by the
std::contiguous_iterator concept. This is also consistent with the
naming conventions in the working paper.
* include/std/span (span): Reorder members and rename template
parameters to match declarations in the C++2a working paper.
Tested powerpc64le-linux, committed to trunk.
commit f09f32427b21127af0ec4c4a48dc9f3b0e696e59
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Tue Feb 18 12:33:07 2020 +0000
libstdc++: Reorder declarations of std::span members
I find it easier to work with this class when the declarations match the
order in the C++2a working paper.
There's no need to use long, descriptive template parameter names like
_ContiguousIterator when the parameter is already constrained by the
std::contiguous_iterator concept. This is also consistent with the
naming conventions in the working paper.
* include/std/span (span): Reorder members and rename template
parameters to match declarations in the C++2a working paper.
diff --git a/libstdc++-v3/include/std/span b/libstdc++-v3/include/std/span
index b8d5e0797a2..feb1c1f46ad 100644
--- a/libstdc++-v3/include/std/span
+++ b/libstdc++-v3/include/std/span
@@ -140,25 +140,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
public:
// member types
- using value_type = remove_cv_t<_Type>;
using element_type = _Type;
+ using value_type = remove_cv_t<_Type>;
using size_type = size_t;
- using reference = element_type&;
- using const_reference = const element_type&;
+ using difference_type = ptrdiff_t;
using pointer = _Type*;
using const_pointer = const _Type*;
- using iterator
- = __gnu_cxx::__normal_iterator<pointer, span>;
- using const_iterator
- = __gnu_cxx::__normal_iterator<const_pointer, span>;
+ using reference = element_type&;
+ using const_reference = const element_type&;
+ using iterator = __gnu_cxx::__normal_iterator<pointer, span>;
+ using const_iterator = __gnu_cxx::__normal_iterator<const_pointer, span>;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
- using difference_type = ptrdiff_t;
// member constants
- static inline constexpr size_t extent = _Extent;
+ static constexpr size_t extent = _Extent;
- // constructors
+ // constructors, copy and assignment
constexpr
span() noexcept
@@ -166,8 +164,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: _M_extent(0), _M_ptr(nullptr)
{ }
- constexpr
- span(const span&) noexcept = default;
+ template<contiguous_iterator _It>
+ requires (__is_compatible_iterator<_It>::value)
+ constexpr
+ span(_It __first, size_type __count)
+ noexcept
+ : _M_extent(__count), _M_ptr(std::to_address(__first))
+ { __glibcxx_assert(_Extent == dynamic_extent || __count == _Extent); }
+
+ template<contiguous_iterator _It, sized_sentinel_for<_It> _End>
+ requires (__is_compatible_iterator<_It>::value)
+ && (!is_convertible_v<_End, size_type>)
+ constexpr
+ span(_It __first, _End __last)
+ noexcept(noexcept(__last - __first))
+ : _M_extent(static_cast<size_type>(__last - __first)),
+ _M_ptr(std::to_address(__first))
+ {
+ if (_Extent != dynamic_extent)
+ __glibcxx_assert((__last - __first) == _Extent);
+ }
template<typename _Tp, size_t _ArrayExtent>
requires (__is_compatible_array<_Tp, _ArrayExtent>::value)
@@ -203,27 +219,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: span(ranges::data(__range), ranges::size(__range))
{ }
- template<contiguous_iterator _ContiguousIterator,
- sized_sentinel_for<_ContiguousIterator> _Sentinel>
- requires (__is_compatible_iterator<_ContiguousIterator>::value)
- && (!is_convertible_v<_Sentinel, size_type>)
- constexpr
- span(_ContiguousIterator __first, _Sentinel __last)
- noexcept(noexcept(__last - __first))
- : _M_extent(static_cast<size_type>(__last - __first)),
- _M_ptr(std::to_address(__first))
- {
- if (_Extent != dynamic_extent)
- __glibcxx_assert((__last - __first) == _Extent);
- }
-
- template<contiguous_iterator _ContiguousIterator>
- requires (__is_compatible_iterator<_ContiguousIterator>::value)
- constexpr
- span(_ContiguousIterator __first, size_type __count)
- noexcept
- : _M_extent(__count), _M_ptr(std::to_address(__first))
- { __glibcxx_assert(_Extent == dynamic_extent || __count == _Extent); }
+ constexpr
+ span(const span&) noexcept = default;
template<typename _OType, size_t _OExtent>
requires (_Extent == dynamic_extent || _Extent == _OExtent)
@@ -233,7 +230,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: _M_extent(__s.size()), _M_ptr(__s.data())
{ }
- // assignment
+ ~span() noexcept = default;
constexpr span&
operator=(const span&) noexcept = default;
@@ -414,8 +411,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
span(const array<_Type, _ArrayExtent>&)
-> span<const _Type, _ArrayExtent>;
- template<contiguous_iterator _Iter, typename _Sentinel>
- span(_Iter, _Sentinel)
+ template<contiguous_iterator _Iter, typename _End>
+ span(_Iter, _End)
-> span<remove_reference_t<iter_reference_t<_Iter>>>;
template<typename _Range>
