replace ArrayRange by tcb::span (reproduction of std::span)
This commit is contained in:
Garux
@@ -20,48 +20,10 @@
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*/
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#pragma once
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#include "span.h"
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/// \file
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/// \brief Macros for automatically converting a compile-time-sized array to a range.
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using tcb::Span;
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template<typename Element>
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struct ArrayRange
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{
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typedef Element* Iterator;
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ArrayRange( Iterator first, Iterator last )
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: first( first ), last( last ){
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}
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Iterator first;
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Iterator last;
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};
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using StringArrayRange = Span<const char *const>;
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template<typename Element>
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inline ArrayRange<Element> makeArrayRange( Element* first, Element* last ){
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return ArrayRange<Element>( first, last );
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}
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template<typename Element>
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struct ArrayConstRange
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{
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typedef const Element* Iterator;
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ArrayConstRange( Iterator first, Iterator last )
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: first( first ), last( last ){
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}
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Iterator first;
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Iterator last;
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};
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template<typename Element>
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inline ArrayConstRange<Element> makeArrayRange( const Element* first, const Element* last ){
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return ArrayConstRange<Element>( first, last );
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}
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#define ARRAY_SIZE( array ) ( sizeof( array ) / sizeof( *array ) )
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#define ARRAY_END( array ) ( array + ARRAY_SIZE( array ) )
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#define ARRAY_RANGE( array ) ( makeArrayRange( array, ARRAY_END( array ) ) )
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typedef ArrayConstRange<const char*> StringArrayRange;
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#define STRING_ARRAY_RANGE( array ) ( StringArrayRange( array, ARRAY_END( array ) ) )
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typedef ArrayRange<const char> StringRange;
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using StringRange = Span<const char>;
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459
libs/generic/span.h
Normal file
459
libs/generic/span.h
Normal file
@@ -0,0 +1,459 @@
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/*
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This is an implementation of C++20's std::span
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http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/n4820.pdf
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*/
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// Copyright Tristan Brindle 2018.
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file ../../LICENSE_1_0.txt or copy at
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// https://www.boost.org/LICENSE_1_0.txt)
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// https://github.com/tcbrindle/span/blob/master/include/tcb/span.hpp
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#pragma once
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#include <array>
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#include <cstddef>
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#include <cstdint>
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#include <type_traits>
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#if !defined(NDEBUG)
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#include <stdexcept>
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#endif
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namespace tcb {
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// Establish default contract checking behavior
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#if !defined(NDEBUG)
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[[noreturn]] inline void contract_violation(const char* /*unused*/)
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{
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std::terminate();
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}
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#define TCB_SPAN_STRINGIFY(cond) #cond
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#define TCB_SPAN_EXPECT(cond) \
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cond ? (void) 0 : contract_violation("Expected " TCB_SPAN_STRINGIFY(cond))
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#else
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#define TCB_SPAN_EXPECT(cond)
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#endif
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inline constexpr std::size_t dynamic_extent = SIZE_MAX;
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template <typename ElementType, std::size_t Extent = dynamic_extent>
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class Span;
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namespace detail {
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template <typename E, std::size_t S>
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struct span_storage {
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constexpr span_storage() noexcept = default;
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constexpr span_storage(E* p_ptr, std::size_t /*unused*/) noexcept
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: ptr(p_ptr)
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{}
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E* ptr = nullptr;
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static constexpr std::size_t size = S;
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};
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template <typename E>
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struct span_storage<E, dynamic_extent> {
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constexpr span_storage() noexcept = default;
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constexpr span_storage(E* p_ptr, std::size_t p_size) noexcept
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: ptr(p_ptr), size(p_size)
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{}
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E* ptr = nullptr;
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std::size_t size = 0;
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};
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using std::data;
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using std::size;
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using std::void_t;
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template <typename T>
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using uncvref_t =
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typename std::remove_cv<typename std::remove_reference<T>::type>::type;
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template <typename>
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struct is_span : std::false_type {};
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template <typename T, std::size_t S>
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struct is_span<Span<T, S>> : std::true_type {};
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template <typename>
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struct is_std_array : std::false_type {};
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template <typename T, std::size_t N>
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struct is_std_array<std::array<T, N>> : std::true_type {};
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template <typename, typename = void>
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struct has_size_and_data : std::false_type {};
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template <typename T>
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struct has_size_and_data<T, void_t<decltype(detail::size(std::declval<T>())),
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decltype(detail::data(std::declval<T>()))>>
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: std::true_type {};
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template <typename C, typename U = uncvref_t<C>>
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struct is_container {
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static constexpr bool value =
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!is_span<U>::value && !is_std_array<U>::value &&
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!std::is_array<U>::value && has_size_and_data<C>::value;
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};
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template <typename T>
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using remove_pointer_t = typename std::remove_pointer<T>::type;
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template <typename, typename, typename = void>
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struct is_container_element_type_compatible : std::false_type {};
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template <typename T, typename E>
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struct is_container_element_type_compatible<
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T, E,
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typename std::enable_if<
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!std::is_same<typename std::remove_cv<decltype(
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detail::data(std::declval<T>()))>::type,
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void>::value>::type>
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: std::is_convertible<
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remove_pointer_t<decltype(detail::data(std::declval<T>()))> (*)[],
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E (*)[]> {};
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template <typename, typename = size_t>
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struct is_complete : std::false_type {};
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template <typename T>
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struct is_complete<T, decltype(sizeof(T))> : std::true_type {};
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} // namespace detail
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template <typename ElementType, std::size_t Extent>
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class Span {
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static_assert(std::is_object<ElementType>::value,
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"A span's ElementType must be an object type (not a "
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"reference type or void)");
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static_assert(detail::is_complete<ElementType>::value,
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"A span's ElementType must be a complete type (not a forward "
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"declaration)");
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static_assert(!std::is_abstract<ElementType>::value,
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"A span's ElementType cannot be an abstract class type");
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using storage_type = detail::span_storage<ElementType, Extent>;
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public:
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// constants and types
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using element_type = ElementType;
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using value_type = typename std::remove_cv<ElementType>::type;
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using size_type = std::size_t;
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using difference_type = std::ptrdiff_t;
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using pointer = element_type*;
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using const_pointer = const element_type*;
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using reference = element_type&;
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using const_reference = const element_type&;
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using iterator = pointer;
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using reverse_iterator = std::reverse_iterator<iterator>;
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static constexpr size_type extent = Extent;
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// [span.cons], span constructors, copy, assignment, and destructor
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template <
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std::size_t E = Extent,
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typename std::enable_if<(E == dynamic_extent || E <= 0), int>::type = 0>
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constexpr Span() noexcept
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{}
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constexpr Span(pointer ptr, size_type count)
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: storage_(ptr, count)
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{
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TCB_SPAN_EXPECT(extent == dynamic_extent || count == extent);
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}
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constexpr Span(pointer first_elem, pointer last_elem)
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: storage_(first_elem, last_elem - first_elem)
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{
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TCB_SPAN_EXPECT(extent == dynamic_extent ||
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last_elem - first_elem ==
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static_cast<std::ptrdiff_t>(extent));
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}
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template <std::size_t N, std::size_t E = Extent,
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typename std::enable_if<
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(E == dynamic_extent || N == E) &&
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detail::is_container_element_type_compatible<
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element_type (&)[N], ElementType>::value,
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int>::type = 0>
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constexpr Span(element_type (&arr)[N]) noexcept : storage_(arr, N)
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{}
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template <std::size_t N, std::size_t E = Extent,
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typename std::enable_if<
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(E == dynamic_extent || N == E) &&
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detail::is_container_element_type_compatible<
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std::array<value_type, N>&, ElementType>::value,
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int>::type = 0>
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constexpr Span(std::array<value_type, N>& arr) noexcept
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: storage_(arr.data(), N)
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{}
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template <std::size_t N, std::size_t E = Extent,
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typename std::enable_if<
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(E == dynamic_extent || N == E) &&
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detail::is_container_element_type_compatible<
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const std::array<value_type, N>&, ElementType>::value,
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int>::type = 0>
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constexpr Span(const std::array<value_type, N>& arr) noexcept
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: storage_(arr.data(), N)
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{}
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template <
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typename Container, std::size_t E = Extent,
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typename std::enable_if<
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E == dynamic_extent && detail::is_container<Container>::value &&
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detail::is_container_element_type_compatible<
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Container&, ElementType>::value,
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int>::type = 0>
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constexpr Span(Container& cont)
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: storage_(detail::data(cont), detail::size(cont))
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{}
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template <
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typename Container, std::size_t E = Extent,
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typename std::enable_if<
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E == dynamic_extent && detail::is_container<Container>::value &&
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detail::is_container_element_type_compatible<
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const Container&, ElementType>::value,
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int>::type = 0>
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constexpr Span(const Container& cont)
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: storage_(detail::data(cont), detail::size(cont))
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{}
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constexpr Span(const Span& other) noexcept = default;
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template <typename OtherElementType, std::size_t OtherExtent,
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typename std::enable_if<
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(Extent == OtherExtent || Extent == dynamic_extent) &&
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std::is_convertible<OtherElementType (*)[],
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ElementType (*)[]>::value,
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int>::type = 0>
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constexpr Span(const Span<OtherElementType, OtherExtent>& other) noexcept
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: storage_(other.data(), other.size())
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{}
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~Span() noexcept = default;
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constexpr Span&
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operator=(const Span& other) noexcept = default;
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// [span.sub], span subviews
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template <std::size_t Count>
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constexpr Span<element_type, Count> first() const
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{
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TCB_SPAN_EXPECT(Count <= size());
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return {data(), Count};
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}
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template <std::size_t Count>
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constexpr Span<element_type, Count> last() const
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{
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TCB_SPAN_EXPECT(Count <= size());
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return {data() + (size() - Count), Count};
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}
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template <std::size_t Offset, std::size_t Count = dynamic_extent>
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using subspan_return_t =
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Span<ElementType, Count != dynamic_extent
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? Count
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: (Extent != dynamic_extent ? Extent - Offset
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: dynamic_extent)>;
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template <std::size_t Offset, std::size_t Count = dynamic_extent>
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constexpr subspan_return_t<Offset, Count> subspan() const
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{
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TCB_SPAN_EXPECT(Offset <= size() &&
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(Count == dynamic_extent || Offset + Count <= size()));
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return {data() + Offset,
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Count != dynamic_extent ? Count : size() - Offset};
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}
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constexpr Span<element_type, dynamic_extent>
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first(size_type count) const
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{
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TCB_SPAN_EXPECT(count <= size());
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return {data(), count};
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}
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constexpr Span<element_type, dynamic_extent>
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last(size_type count) const
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{
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TCB_SPAN_EXPECT(count <= size());
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return {data() + (size() - count), count};
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}
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constexpr Span<element_type, dynamic_extent>
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subspan(size_type offset, size_type count = dynamic_extent) const
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{
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TCB_SPAN_EXPECT(offset <= size() &&
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(count == dynamic_extent || offset + count <= size()));
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return {data() + offset,
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count == dynamic_extent ? size() - offset : count};
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}
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// [span.obs], span observers
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constexpr size_type size() const noexcept { return storage_.size; }
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constexpr size_type size_bytes() const noexcept
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{
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return size() * sizeof(element_type);
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}
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[[nodiscard]] constexpr bool empty() const noexcept
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{
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return size() == 0;
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}
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// [span.elem], span element access
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constexpr reference operator[](size_type idx) const
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{
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TCB_SPAN_EXPECT(idx < size());
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return *(data() + idx);
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}
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constexpr reference front() const
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{
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TCB_SPAN_EXPECT(!empty());
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return *data();
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}
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constexpr reference back() const
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{
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TCB_SPAN_EXPECT(!empty());
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return *(data() + (size() - 1));
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}
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constexpr pointer data() const noexcept { return storage_.ptr; }
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// [span.iterators], span iterator support
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constexpr iterator begin() const noexcept { return data(); }
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constexpr iterator end() const noexcept { return data() + size(); }
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constexpr reverse_iterator rbegin() const noexcept
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{
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return reverse_iterator(end());
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}
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constexpr reverse_iterator rend() const noexcept
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{
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return reverse_iterator(begin());
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}
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private:
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storage_type storage_{};
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};
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/* Deduction Guides */
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template <class T, size_t N>
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Span(T (&)[N])->Span<T, N>;
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template <class T, size_t N>
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Span(std::array<T, N>&)->Span<T, N>;
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template <class T, size_t N>
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Span(const std::array<T, N>&)->Span<const T, N>;
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template <class Container>
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Span(Container&)->Span<typename Container::value_type>;
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template <class Container>
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Span(const Container&)->Span<const typename Container::value_type>;
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template <typename ElementType, std::size_t Extent>
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constexpr Span<ElementType, Extent>
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make_span(Span<ElementType, Extent> s) noexcept
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{
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return s;
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}
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template <typename T, std::size_t N>
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constexpr Span<T, N> make_span(T (&arr)[N]) noexcept
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{
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return {arr};
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}
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template <typename T, std::size_t N>
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constexpr Span<T, N> make_span(std::array<T, N>& arr) noexcept
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{
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return {arr};
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}
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template <typename T, std::size_t N>
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constexpr Span<const T, N>
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make_span(const std::array<T, N>& arr) noexcept
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{
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return {arr};
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}
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template <typename Container>
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constexpr Span<typename Container::value_type> make_span(Container& cont)
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{
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return {cont};
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}
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template <typename Container>
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constexpr Span<const typename Container::value_type>
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make_span(const Container& cont)
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{
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return {cont};
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}
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template <typename ElementType, std::size_t Extent>
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Span<const std::byte, ((Extent == dynamic_extent) ? dynamic_extent
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: sizeof(ElementType) * Extent)>
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as_bytes(Span<ElementType, Extent> s) noexcept
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{
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return {reinterpret_cast<const std::byte*>(s.data()), s.size_bytes()};
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}
|
||||
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||||
template <
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class ElementType, size_t Extent,
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typename std::enable_if<!std::is_const<ElementType>::value, int>::type = 0>
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||||
Span<std::byte, ((Extent == dynamic_extent) ? dynamic_extent
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||||
: sizeof(ElementType) * Extent)>
|
||||
as_writable_bytes(Span<ElementType, Extent> s) noexcept
|
||||
{
|
||||
return {reinterpret_cast<std::byte*>(s.data()), s.size_bytes()};
|
||||
}
|
||||
|
||||
template <std::size_t N, typename E, std::size_t S>
|
||||
constexpr auto get(Span<E, S> s) -> decltype(s[N])
|
||||
{
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||||
return s[N];
|
||||
}
|
||||
|
||||
} // namespace tcb
|
||||
|
||||
namespace std {
|
||||
|
||||
template <typename ElementType, size_t Extent>
|
||||
class tuple_size<tcb::Span<ElementType, Extent>>
|
||||
: public integral_constant<size_t, Extent> {};
|
||||
|
||||
template <typename ElementType>
|
||||
class tuple_size<tcb::Span<
|
||||
ElementType, tcb::dynamic_extent>>; // not defined
|
||||
|
||||
template <size_t I, typename ElementType, size_t Extent>
|
||||
class tuple_element<I, tcb::Span<ElementType, Extent>> {
|
||||
public:
|
||||
static_assert(Extent != tcb::dynamic_extent &&
|
||||
I < Extent,
|
||||
"");
|
||||
using type = ElementType;
|
||||
};
|
||||
|
||||
} // end namespace std
|
||||
Reference in New Issue
Block a user