mirror of
https://github.com/microsoft/GSL.git
synced 2024-11-03 17:56:43 -05:00
232 lines
7.8 KiB
C++
232 lines
7.8 KiB
C++
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
|
|
//
|
|
// This code is licensed under the MIT License (MIT).
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
// THE SOFTWARE.
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
#pragma once
|
|
|
|
#ifndef GSL_SPAN_H
|
|
#define GSL_SPAN_H
|
|
|
|
#include "gsl_assert.h"
|
|
#include "gsl_util.h"
|
|
#include <array>
|
|
#include <limits>
|
|
#include <iterator>
|
|
#include <stdexcept>
|
|
#include <type_traits>
|
|
#include <utility>
|
|
|
|
#ifdef _MSC_VER
|
|
|
|
// turn off some warnings that are noisy about our Expects statements
|
|
#pragma warning(push)
|
|
#pragma warning(disable : 4127) // conditional expression is constant
|
|
|
|
// No MSVC does constexpr fully yet
|
|
#pragma push_macro("constexpr")
|
|
#define constexpr
|
|
|
|
// VS 2013 workarounds
|
|
#if _MSC_VER <= 1800
|
|
|
|
#define GSL_MSVC_HAS_VARIADIC_CTOR_BUG
|
|
#define GSL_MSVC_NO_SUPPORT_FOR_MOVE_CTOR_DEFAULT
|
|
|
|
// noexcept is not understood
|
|
#ifndef GSL_THROW_ON_CONTRACT_VIOLATION
|
|
#pragma push_macro("noexcept")
|
|
#define noexcept /* nothing */
|
|
#endif
|
|
|
|
// turn off some misguided warnings
|
|
#pragma warning(push)
|
|
#pragma warning(disable : 4351) // warns about newly introduced aggregate initializer behavior
|
|
#pragma warning(disable : 4512) // warns that assignment op could not be generated
|
|
|
|
#endif // _MSC_VER <= 1800
|
|
|
|
#endif // _MSC_VER
|
|
|
|
#ifdef GSL_THROW_ON_CONTRACT_VIOLATION
|
|
|
|
#ifdef _MSC_VER
|
|
#pragma push_macro("noexcept")
|
|
#endif
|
|
|
|
#define noexcept /* nothing */
|
|
|
|
#endif // GSL_THROW_ON_CONTRACT_VIOLATION
|
|
|
|
namespace gsl
|
|
{
|
|
|
|
// [views.constants], constants
|
|
constexpr const std::ptrdiff_t dynamic_extent = -1;
|
|
|
|
|
|
// [span], class template span
|
|
template <class ElementType, std::ptrdiff_t Extent = dynamic_extent>
|
|
class span {
|
|
public:
|
|
// constants and types
|
|
using element_type = ElementType;
|
|
using index_type = std::ptrdiff_t;
|
|
using pointer = element_type*;
|
|
using reference = element_type&;
|
|
#if 0 // TODO
|
|
using iterator = /*implementation-defined */;
|
|
using const_iterator = /* implementation-defined */;
|
|
using reverse_iterator = std::reverse_iterator<iterator>;
|
|
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
|
|
#endif
|
|
constexpr static const index_type extent = Extent;
|
|
|
|
// [span.cons], span constructors, copy, assignment, and destructor
|
|
constexpr span() noexcept : data_(nullptr), size_(0)
|
|
{ static_assert(extent == dynamic_extent || extent == 0, "Cannot default initialize a fixed-length span."); }
|
|
constexpr span(nullptr_t) noexcept : span() {}
|
|
constexpr span(pointer ptr, index_type count) : data_(ptr), size_(count)
|
|
{ Expects((!ptr && count == 0) || (ptr && count >= 0)); }
|
|
#if 0 // TODO
|
|
constexpr span(pointer firstElem, pointer lastElem);
|
|
template <size_t N>
|
|
constexpr span(element_type(&arr)[N]);
|
|
template <size_t N>
|
|
constexpr span(array<remove_const_t<element_type>, N>& arr);
|
|
template <size_t N>
|
|
constexpr span(const array<remove_const_t<element_type>, N>& arr);
|
|
template <class Container>
|
|
constexpr span(Container& cont);
|
|
template <class Container>
|
|
span(const Container&&) = delete;
|
|
constexpr span(const span& other) noexcept = default;
|
|
constexpr span(span&& other) noexcept = default;
|
|
template <class OtherElementType, ptrdiff_t OtherExtent>
|
|
constexpr span(const span<OtherElementType, OtherExtent>& other);
|
|
template <class OtherElementType, ptrdiff_t OtherExtent>
|
|
constexpr span(span<OtherElementType, OtherExtent>&& other);
|
|
~span() noexcept = default;
|
|
constexpr span& operator=(const span& other) noexcept = default;
|
|
constexpr span& operator=(span&& other) noexcept = default;
|
|
|
|
// [span.sub], span subviews
|
|
template <ptrdiff_t Count>
|
|
constexpr span<element_type, Count> first() const;
|
|
template <ptrdiff_t Count>
|
|
constexpr span<element_type, Count> last() const;
|
|
template <ptrdiff_t Offset, ptrdiff_t Count = dynamic_extent>
|
|
constexpr span<element_type, Count> subspan() const;
|
|
constexpr span<element_type, dynamic_extent> first(index_type count) const;
|
|
constexpr span<element_type, dynamic_extent> last(index_type count) const;
|
|
constexpr span<element_type, dynamic_extent> subspan(index_type offset, index_type count = dynamic_extent) const;
|
|
#endif
|
|
// [span.obs], span observers
|
|
constexpr index_type length() const noexcept { return size(); }
|
|
constexpr index_type size() const noexcept { return size_; }
|
|
constexpr index_type length_bytes() const noexcept { return size_bytes(); }
|
|
constexpr index_type size_bytes() const noexcept { return size() * sizeof(element_type); }
|
|
constexpr bool empty() const noexcept { return size() == 0; }
|
|
|
|
#if 0 // TODO
|
|
// [span.elem], span element access
|
|
constexpr reference operator[](index_type idx) const;
|
|
constexpr reference operator()(index_type idx) const;
|
|
#endif
|
|
constexpr pointer data() const noexcept { return data_; }
|
|
#if 0 // TODO
|
|
// [span.iter], span iterator support
|
|
iterator begin() const noexcept;
|
|
iterator end() const noexcept;
|
|
|
|
const_iterator cbegin() const noexcept;
|
|
const_iterator cend() const noexcept;
|
|
|
|
reverse_iterator rbegin() const noexcept;
|
|
reverse_iterator rend() const noexcept;
|
|
|
|
const_reverse_iterator crbegin() const noexcept;
|
|
const_reverse_iterator crend() const noexcept;
|
|
#endif
|
|
private:
|
|
pointer data_;
|
|
index_type size_;
|
|
};
|
|
|
|
|
|
#if 0 // TODO
|
|
// [span.comparison], span comparison operators
|
|
template <class ElementType, ptrdiff_t Extent>
|
|
constexpr bool operator==(const span<ElementType, Extent>& l, const span<ElementType, Extent>& r) const noexcept;
|
|
|
|
template <class ElementType, ptrdiff_t Extent>
|
|
constexpr bool operator!=(const span<ElementType, Extent>& l, const span<ElementType, Extent>& r) const noexcept;
|
|
|
|
template <class ElementType, ptrdiff_t Extent>
|
|
constexpr bool operator<(const span<ElementType, Extent>& l, const span<ElementType, Extent>& r) const noexcept;
|
|
|
|
template <class ElementType, ptrdiff_t Extent>
|
|
constexpr bool operator<=(const span<ElementType, Extent>& l, const span<ElementType, Extent>& r) const noexcept;
|
|
|
|
template <class ElementType, ptrdiff_t Extent>
|
|
constexpr bool operator>(const span<ElementType, Extent>& l, const span<ElementType, Extent>& r) const noexcept;
|
|
|
|
template <class ElementType, ptrdiff_t Extent>
|
|
constexpr bool operator>=(const span<ElementType, Extent>& l, const span<ElementType, Extent>& r) const noexcept;
|
|
#endif
|
|
|
|
|
|
#if 0 // TODO
|
|
// [span.objectrep], views of object representation
|
|
template <class ElementType, ptrdiff_t Extent>
|
|
constexpr span<const char, ((Extent == dynamic_extent) ? dynamic_extent : (sizeof(ElementType) * Extent))> as_bytes(span<ElementType, Extent> s) noexcept;
|
|
|
|
template <class ElementType, ptrdiff_t Extent>
|
|
constexpr span<char, ((Extent == dynamic_extent) ? dynamic_extent : (sizeof(ElementType) * Extent))> as_writeable_bytes(span<ElementType, Extent>) noexcept;
|
|
#endif
|
|
|
|
} // namespace gsl
|
|
|
|
#ifdef _MSC_VER
|
|
|
|
#undef constexpr
|
|
#pragma pop_macro("constexpr")
|
|
|
|
#if _MSC_VER <= 1800
|
|
#pragma warning(pop)
|
|
|
|
#ifndef GSL_THROW_ON_CONTRACT_VIOLATION
|
|
#undef noexcept
|
|
#pragma pop_macro("noexcept")
|
|
#endif // GSL_THROW_ON_CONTRACT_VIOLATION
|
|
|
|
#undef GSL_MSVC_HAS_VARIADIC_CTOR_BUG
|
|
|
|
#endif // _MSC_VER <= 1800
|
|
|
|
#endif // _MSC_VER
|
|
|
|
#if defined(GSL_THROW_ON_CONTRACT_VIOLATION)
|
|
|
|
#undef noexcept
|
|
|
|
#ifdef _MSC_VER
|
|
#pragma warning(pop)
|
|
#pragma pop_macro("noexcept")
|
|
#endif
|
|
|
|
#endif // GSL_THROW_ON_CONTRACT_VIOLATION
|
|
|
|
#endif // GSL_SPAN_H
|