[v2,3/3] libcamera: base: span: Remove

28154 diff mbox series

diff --git a/include/libcamera/base/span.h b/include/libcamera/base/span.h
index 5c7a98d8e7..ca10aa2954 100644
--- a/include/libcamera/base/span.h
+++ b/include/libcamera/base/span.h
@@ -7,408 +7,13 @@ 
 
 #pragma once
 
-#include <array>
-#include <iterator>
-#include <limits>
-#include <type_traits>
+#include <span>
 
-namespace libcamera {
-
-static constexpr std::size_t dynamic_extent = std::numeric_limits<std::size_t>::max();
-
-template<typename T, std::size_t Extent = dynamic_extent>
-class Span;
-
-namespace details {
-
-template<typename U>
-struct is_array : public std::false_type {
-};
-
-template<typename U, std::size_t N>
-struct is_array<std::array<U, N>> : public std::true_type {
-};
-
-template<typename U>
-struct is_libcamera_span : public std::false_type {
-};
-
-template<typename U, std::size_t Extent>
-struct is_libcamera_span<Span<U, Extent>> : public std::true_type {
-};
-
-} /* namespace details */
-
-namespace utils {
-
-template<typename C>
-constexpr auto size(const C &c) -> decltype(c.size())
-{
-	return c.size();
-}
-
-template<typename C>
-constexpr auto data(const C &c) -> decltype(c.data())
-{
-	return c.data();
-}
-
-template<typename C>
-constexpr auto data(C &c) -> decltype(c.data())
-{
-	return c.data();
-}
-
-template<class T, std::size_t N>
-constexpr T *data(T (&array)[N]) noexcept
-{
-	return array;
-}
-
-template<std::size_t I, typename T>
-struct tuple_element;
-
-template<std::size_t I, typename T, std::size_t N>
-struct tuple_element<I, Span<T, N>> {
-	using type = T;
-};
-
-template<typename T>
-struct tuple_size;
-
-template<typename T, std::size_t N>
-struct tuple_size<Span<T, N>> : public std::integral_constant<std::size_t, N> {
-};
-
-template<typename T>
-struct tuple_size<Span<T, dynamic_extent>>;
-
-} /* namespace utils */
-
-template<typename T, std::size_t Extent>
-class Span
-{
-public:
-	using element_type = T;
-	using value_type = typename std::remove_cv_t<T>;
-	using size_type = std::size_t;
-	using difference_type = std::ptrdiff_t;
-	using pointer = T *;
-	using const_pointer = const T *;
-	using reference = T &;
-	using const_reference = const T &;
-	using iterator = pointer;
-	using const_iterator = const_pointer;
-	using reverse_iterator = std::reverse_iterator<iterator>;
-	using const_reverse_iterator = std::reverse_iterator<const_iterator>;
-
-	static constexpr std::size_t extent = Extent;
-
-	template<bool Dependent = false,
-		 typename = std::enable_if_t<Dependent || Extent == 0>>
-	constexpr Span() noexcept
-		: data_(nullptr)
-	{
-	}
-
-	explicit constexpr Span(pointer ptr, [[maybe_unused]] size_type count)
-		: data_(ptr)
-	{
-	}
-
-	explicit constexpr Span(pointer first, [[maybe_unused]] pointer last)
-		: data_(first)
-	{
-	}
-
-	template<std::size_t N>
-	constexpr Span(element_type (&arr)[N],
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value &&
-					N == Extent,
-					std::nullptr_t> = nullptr) noexcept
-		: data_(arr)
-	{
-	}
-
-	template<std::size_t N>
-	constexpr Span(std::array<value_type, N> &arr,
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value &&
-					N == Extent,
-					std::nullptr_t> = nullptr) noexcept
-		: data_(arr.data())
-	{
-	}
-
-	template<std::size_t N>
-	constexpr Span(const std::array<value_type, N> &arr,
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value &&
-					N == Extent,
-					std::nullptr_t> = nullptr) noexcept
-		: data_(arr.data())
-	{
-	}
-
-	template<class Container>
-	explicit constexpr Span(Container &cont,
-				std::enable_if_t<!details::is_libcamera_span<Container>::value &&
-						 !details::is_array<Container>::value &&
-						 !std::is_array<Container>::value &&
-						 std::is_convertible<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
-								     element_type (*)[]>::value,
-						 std::nullptr_t> = nullptr)
-		: data_(utils::data(cont))
-	{
-	}
-
-	template<class Container>
-	explicit constexpr Span(const Container &cont,
-				std::enable_if_t<!details::is_libcamera_span<Container>::value &&
-						 !details::is_array<Container>::value &&
-						 !std::is_array<Container>::value &&
-						 std::is_convertible<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
-								     element_type (*)[]>::value,
-						 std::nullptr_t> = nullptr)
-		: data_(utils::data(cont))
-	{
-		static_assert(utils::size(cont) == Extent, "Size mismatch");
-	}
-
-	template<class U, std::size_t N>
-	explicit constexpr Span(const Span<U, N> &s,
-				std::enable_if_t<std::is_convertible<U (*)[], element_type (*)[]>::value &&
-						 N == Extent,
-						 std::nullptr_t> = nullptr) noexcept
-		: data_(s.data())
-	{
-	}
-
-	constexpr Span(const Span &other) noexcept = default;
-	constexpr Span &operator=(const Span &other) noexcept = default;
+/* \todo Remove this header. */
 
-	constexpr iterator begin() const { return data(); }
-	constexpr const_iterator cbegin() const { return begin(); }
-	constexpr iterator end() const { return data() + size(); }
-	constexpr const_iterator cend() const { return end(); }
-	constexpr reverse_iterator rbegin() const { return reverse_iterator(end()); }
-	constexpr const_reverse_iterator crbegin() const { return rbegin(); }
-	constexpr reverse_iterator rend() const { return reverse_iterator(begin()); }
-	constexpr const_reverse_iterator crend() const { return rend(); }
-
-	constexpr reference front() const { return *data(); }
-	constexpr reference back() const { return *(data() + size() - 1); }
-	constexpr reference operator[](size_type idx) const { return data()[idx]; }
-	constexpr pointer data() const noexcept { return data_; }
-
-	constexpr size_type size() const noexcept { return Extent; }
-	constexpr size_type size_bytes() const noexcept { return size() * sizeof(element_type); }
-	constexpr bool empty() const noexcept { return size() == 0; }
-
-	template<std::size_t Count>
-	constexpr Span<element_type, Count> first() const
-	{
-		static_assert(Count <= Extent, "Count larger than size");
-		return Span<element_type, Count>{ data(), Count };
-	}
-
-	constexpr Span<element_type, dynamic_extent> first(std::size_t Count) const
-	{
-		return Span<element_type, dynamic_extent>{ data(), Count };
-	}
-
-	template<std::size_t Count>
-	constexpr Span<element_type, Count> last() const
-	{
-		static_assert(Count <= Extent, "Count larger than size");
-		return Span<element_type, Count>{ data() + size() - Count, Count };
-	}
-
-	constexpr Span<element_type, dynamic_extent> last(std::size_t Count) const
-	{
-		return Span<element_type, dynamic_extent>{ data() + size() - Count, Count };
-	}
-
-	template<std::size_t Offset, std::size_t Count = dynamic_extent>
-	constexpr Span<element_type, Count != dynamic_extent ? Count : Extent - Offset> subspan() const
-	{
-		static_assert(Offset <= Extent, "Offset larger than size");
-		static_assert(Count == dynamic_extent || Count + Offset <= Extent,
-			      "Offset + Count larger than size");
-		return Span<element_type, Count != dynamic_extent ? Count : Extent - Offset>{
-			data() + Offset,
-			Count == dynamic_extent ? size() - Offset : Count
-		};
-	}
-
-	constexpr Span<element_type, dynamic_extent>
-	subspan(std::size_t Offset, std::size_t Count = dynamic_extent) const
-	{
-		return Span<element_type, dynamic_extent>{
-			data() + Offset,
-			Count == dynamic_extent ? size() - Offset : Count
-		};
-	}
-
-private:
-	pointer data_;
-};
-
-template<typename T>
-class Span<T, dynamic_extent>
-{
-public:
-	using element_type = T;
-	using value_type = typename std::remove_cv_t<T>;
-	using size_type = std::size_t;
-	using difference_type = std::ptrdiff_t;
-	using pointer = T *;
-	using const_pointer = const T *;
-	using reference = T &;
-	using const_reference = const T &;
-	using iterator = T *;
-	using const_iterator = const T *;
-	using reverse_iterator = std::reverse_iterator<iterator>;
-	using const_reverse_iterator = std::reverse_iterator<const_iterator>;
-
-	static constexpr std::size_t extent = dynamic_extent;
-
-	constexpr Span() noexcept
-		: data_(nullptr), size_(0)
-	{
-	}
-
-	constexpr Span(pointer ptr, size_type count)
-		: data_(ptr), size_(count)
-	{
-	}
-
-	constexpr Span(pointer first, pointer last)
-		: data_(first), size_(last - first)
-	{
-	}
-
-	template<std::size_t N>
-	constexpr Span(element_type (&arr)[N],
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value,
-					std::nullptr_t> = nullptr) noexcept
-		: data_(arr), size_(N)
-	{
-	}
-
-	template<std::size_t N>
-	constexpr Span(std::array<value_type, N> &arr,
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value,
-					std::nullptr_t> = nullptr) noexcept
-		: data_(utils::data(arr)), size_(N)
-	{
-	}
-
-	template<std::size_t N>
-	constexpr Span(const std::array<value_type, N> &arr) noexcept
-		: data_(utils::data(arr)), size_(N)
-	{
-	}
-
-	template<class Container>
-	constexpr Span(Container &cont,
-		       std::enable_if_t<!details::is_libcamera_span<Container>::value &&
-					!details::is_array<Container>::value &&
-					!std::is_array<Container>::value &&
-					std::is_convertible<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
-							    element_type (*)[]>::value,
-					std::nullptr_t> = nullptr)
-		: data_(utils::data(cont)), size_(utils::size(cont))
-	{
-	}
-
-	template<class Container>
-	constexpr Span(const Container &cont,
-		       std::enable_if_t<!details::is_libcamera_span<Container>::value &&
-					!details::is_array<Container>::value &&
-					!std::is_array<Container>::value &&
-					std::is_convertible<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
-							    element_type (*)[]>::value,
-					std::nullptr_t> = nullptr)
-		: data_(utils::data(cont)), size_(utils::size(cont))
-	{
-	}
-
-	template<class U, std::size_t N>
-	constexpr Span(const Span<U, N> &s,
-		       std::enable_if_t<std::is_convertible<U (*)[], element_type (*)[]>::value,
-					std::nullptr_t> = nullptr) noexcept
-		: data_(s.data()), size_(s.size())
-	{
-	}
-
-	constexpr Span(const Span &other) noexcept = default;
-	constexpr Span &operator=(const Span &other) noexcept = default;
-
-	constexpr iterator begin() const { return data(); }
-	constexpr const_iterator cbegin() const { return begin(); }
-	constexpr iterator end() const { return data() + size(); }
-	constexpr const_iterator cend() const { return end(); }
-	constexpr reverse_iterator rbegin() const { return reverse_iterator(end()); }
-	constexpr const_reverse_iterator crbegin() const { return rbegin(); }
-	constexpr reverse_iterator rend() const { return reverse_iterator(begin()); }
-	constexpr const_reverse_iterator crend() const { return rend(); }
-
-	constexpr reference front() const { return *data(); }
-	constexpr reference back() const { return *(data() + size() - 1); }
-	constexpr reference operator[](size_type idx) const { return data()[idx]; }
-	constexpr pointer data() const noexcept { return data_; }
-
-	constexpr size_type size() const noexcept { return size_; }
-	constexpr size_type size_bytes() const noexcept { return size() * sizeof(element_type); }
-	constexpr bool empty() const noexcept { return size() == 0; }
-
-	template<std::size_t Count>
-	constexpr Span<element_type, Count> first() const
-	{
-		return Span<element_type, Count>{ data(), Count };
-	}
-
-	constexpr Span<element_type, dynamic_extent> first(std::size_t Count) const
-	{
-		return { data(), Count };
-	}
-
-	template<std::size_t Count>
-	constexpr Span<element_type, Count> last() const
-	{
-		return Span<element_type, Count>{ data() + size() - Count, Count };
-	}
-
-	constexpr Span<element_type, dynamic_extent> last(std::size_t Count) const
-	{
-		return Span<element_type, dynamic_extent>{ data() + size() - Count, Count };
-	}
-
-	template<std::size_t Offset, std::size_t Count = dynamic_extent>
-	constexpr Span<element_type, Count> subspan() const
-	{
-		return Span<element_type, Count>{
-			data() + Offset,
-			Count == dynamic_extent ? size() - Offset : Count
-		};
-	}
-
-	constexpr Span<element_type, dynamic_extent>
-	subspan(std::size_t Offset, std::size_t Count = dynamic_extent) const
-	{
-		return Span<element_type, dynamic_extent>{
-			data() + Offset,
-			Count == dynamic_extent ? size() - Offset : Count
-		};
-	}
+namespace libcamera {
 
-private:
-	pointer data_;
-	size_type size_;
-};
+template<typename T, std::size_t Extent = std::dynamic_extent>
+using Span [[deprecated("use std::span instead")]] = std::span<T, Extent>;
 
 } /* namespace libcamera */
diff --git a/test/meson.build b/test/meson.build
index e4450625ee..363a2829d8 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -45,7 +45,6 @@  public_tests = [
     {'name': 'geometry', 'sources': ['geometry.cpp']},
     {'name': 'public-api', 'sources': ['public-api.cpp']},
     {'name': 'signal', 'sources': ['signal.cpp']},
-    {'name': 'span', 'sources': ['span.cpp']},
     {'name': 'transform', 'sources': ['transform.cpp']},
 ]
 
diff --git a/test/span.cpp b/test/span.cpp
deleted file mode 100644
index 4b9f3279ad..0000000000
--- a/test/span.cpp
+++ /dev/null
@@ -1,205 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Copyright (C) 2020, Google Inc.
- *
- * Span tests
- */
-
-/*
- * Include first to ensure the header is self-contained, as there's no span.cpp
- * in libcamera.
- */
-#include <libcamera/base/span.h>
-
-#include <array>
-#include <iostream>
-#include <vector>
-
-#include "test.h"
-
-using namespace std;
-using namespace libcamera;
-
-class SpanTest : public Test
-{
-protected:
-	int run()
-	{
-		int i[4]{ 1, 2, 3, 4 };
-		std::array<int, 4> a{ 1, 2, 3, 4 };
-		const std::array<int, 4> ca{ 1, 2, 3, 4 };
-		std::vector<int> v{ 1, 2, 3, 4 };
-		const std::vector<int> cv{ 1, 2, 3, 4 };
-
-		/*
-		 * Compile-test construction and usage of spans with static
-		 * extent. Commented-out tests are expected not to compile, or
-		 * to generate undefined behaviour.
-		 */
-
-		Span<int, 0>{};
-		/* Span<int, 4>{}; */
-
-		Span<int, 4>{ &i[0], 4 };
-		Span<int, 4>{ &i[0], &i[3] };
-
-		Span<int, 4>{ i };
-		/* Span<float, 4>{ i }; */
-		/* Span<int, 2>{ i }; */
-
-		Span<int, 4>{ a };
-		Span<const int, 4>{ a };
-		/* Span<float, 4>{ a }; */
-		/* Span<int, 2>{ a }; */
-
-		Span<const int, 4>{ ca };
-		/* Span<const int, 2>{ ca }; */
-		/* Span<const float, 4>{ ca }; */
-		/* Span<int, 4>{ ca }; */
-
-		Span<int, 4>{ v };
-		Span<const int, 4>{ v };
-		/* Span<float, 4>{ v }; */
-
-		Span<const int, 4>{ v };
-		/* Span<int, 4>{ v }; */
-		/* Span<const float, 4>{ v }; */
-
-		Span<int, 4> staticSpan{ i };
-		Span<int, 4>{ staticSpan };
-		Span<const int, 4>{ staticSpan };
-		/* Span<const int, 2>{ staticSpan }; */
-
-		staticSpan = Span<int, 4>{ v };
-
-		if (*staticSpan.begin() != 1) {
-			std::cout << "Span<static_extent>::begin() failed" << std::endl;
-			return TestFail;
-		}
-		if (*staticSpan.cbegin() != 1) {
-			std::cout << "Span<static_extent>::cbegin() failed" << std::endl;
-			return TestFail;
-		}
-		staticSpan.end();
-		staticSpan.cend();
-		if (*staticSpan.rbegin() != 4) {
-			std::cout << "Span<static_extent>::rbegin() failed" << std::endl;
-			return TestFail;
-		}
-		if (*staticSpan.crbegin() != 4) {
-			std::cout << "Span<static_extent>::crbegin() failed" << std::endl;
-			return TestFail;
-		}
-		staticSpan.rend();
-		staticSpan.crend();
-
-		staticSpan.front();
-		staticSpan.back();
-		staticSpan[0];
-		staticSpan.data();
-
-		staticSpan.size();
-		staticSpan.size_bytes();
-
-		staticSpan.empty();
-
-		staticSpan.first<2>();
-		staticSpan.first(2);
-		/* staticSpan.first<6>(); */
-		/* staticSpan.first(6); */
-		staticSpan.last<2>();
-		staticSpan.last(2);
-		/* staticSpan.last<6>(); */
-		/* staticSpan.last(6); */
-		staticSpan.subspan<1>();
-		staticSpan.subspan<1, 2>();
-		staticSpan.subspan(1);
-		staticSpan.subspan(1, 2);
-		/* staticSpan.subspan(2, 4); */
-
-		/*
-		 * Compile-test construction and usage of spans with dynamic
-		 * extent. Commented-out tests are expected not to compile, or
-		 * to generate undefined behaviour.
-		 */
-
-		Span<int>{};
-
-		Span<int>{ &i[0], 4 };
-		Span<int>{ &i[0], &i[3] };
-
-		Span<int>{ i };
-		/* Span<float>{ i }; */
-
-		Span<int>{ a };
-		Span<const int>{ a };
-		/* Span<float>{ a }; */
-
-		Span<const int>{ ca };
-		/* Span<const float>{ca}; */
-		/* Span<int>{ca}; */
-
-		Span<int>{ v };
-		Span<const int>{ v };
-		/* Span<float>{ v }; */
-
-		Span<const int>{ cv };
-		/* Span<int>{ cv }; */
-		/* Span<const float>{ cv }; */
-
-		Span<int> dynamicSpan{ i };
-		Span<int>{ dynamicSpan };
-		Span<const int>{ dynamicSpan };
-
-		dynamicSpan = Span<int>{ a };
-
-		if (*dynamicSpan.begin() != 1) {
-			std::cout << "Span<dynamic_extent>::begin() failed" << std::endl;
-			return TestFail;
-		}
-		if (*dynamicSpan.cbegin() != 1) {
-			std::cout << "Span<dynamic_extent>::cbegin() failed" << std::endl;
-			return TestFail;
-		}
-		dynamicSpan.end();
-		dynamicSpan.cend();
-		if (*dynamicSpan.rbegin() != 4) {
-			std::cout << "Span<dynamic_extent>::rbegin() failed" << std::endl;
-			return TestFail;
-		}
-		if (*dynamicSpan.crbegin() != 4) {
-			std::cout << "Span<dynamic_extent>::crbegin() failed" << std::endl;
-			return TestFail;
-		}
-		dynamicSpan.rend();
-		dynamicSpan.crend();
-
-		dynamicSpan.front();
-		dynamicSpan.back();
-		dynamicSpan[0];
-		dynamicSpan.data();
-
-		dynamicSpan.size();
-		dynamicSpan.size_bytes();
-
-		dynamicSpan.empty();
-
-		dynamicSpan.first<2>();
-		dynamicSpan.first(2);
-		/* dynamicSpan.first<6>(); */
-		/* dynamicSpan.first(6); */
-		dynamicSpan.last<2>();
-		dynamicSpan.last(2);
-		/* dynamicSpan.last<6>(); */
-		/* dynamicSpan.last(6); */
-		dynamicSpan.subspan<1>();
-		dynamicSpan.subspan<1, 2>();
-		dynamicSpan.subspan(1);
-		dynamicSpan.subspan(1, 2);
-		/* dynamicSpan.subspan(2, 4); */
-
-		return TestPass;
-	}
-};
-
-TEST_REGISTER(SpanTest)