# HG changeset patch
# User Patric Stout <truebrain@openttd.org>
# Date 2024-01-16 21:46:00
# Node ID 0d3d4fd5e3623d072386cb48138b7d165a796287
# Parent  779a44bc4e9e1afe7703654563cee622b65a5eb5

Remove: replace custom span with std::span

diff --git a/src/cargotype.cpp b/src/cargotype.cpp
--- a/src/cargotype.cpp
+++ b/src/cargotype.cpp
@@ -158,7 +158,7 @@ SpriteID CargoSpec::GetCargoIcon() const
 
 std::array<uint8_t, NUM_CARGO> _sorted_cargo_types; ///< Sort order of cargoes by cargo ID.
 std::vector<const CargoSpec *> _sorted_cargo_specs;   ///< Cargo specifications sorted alphabetically by name.
-span<const CargoSpec *> _sorted_standard_cargo_specs; ///< Standard cargo specifications sorted alphabetically by name.
+std::span<const CargoSpec *> _sorted_standard_cargo_specs; ///< Standard cargo specifications sorted alphabetically by name.
 
 /** Sort cargo specifications by their name. */
 static bool CargoSpecNameSorter(const CargoSpec * const &a, const CargoSpec * const &b)
diff --git a/src/cargotype.h b/src/cargotype.h
--- a/src/cargotype.h
+++ b/src/cargotype.h
@@ -16,7 +16,6 @@
 #include "strings_type.h"
 #include "landscape_type.h"
 #include "core/bitmath_func.hpp"
-#include "core/span_type.hpp"
 
 /** Globally unique label of a cargo type. */
 typedef uint32_t CargoLabel;
@@ -190,7 +189,7 @@ Dimension GetLargestCargoIconSize();
 void InitializeSortedCargoSpecs();
 extern std::array<uint8_t, NUM_CARGO> _sorted_cargo_types;
 extern std::vector<const CargoSpec *> _sorted_cargo_specs;
-extern span<const CargoSpec *> _sorted_standard_cargo_specs;
+extern std::span<const CargoSpec *> _sorted_standard_cargo_specs;
 
 /**
  * Does cargo \a c have cargo class \a cc?
diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -25,6 +25,5 @@ add_files(
     random_func.hpp
     smallstack_type.hpp
     container_func.hpp
-    span_type.hpp
     strong_typedef_type.hpp
 )
diff --git a/src/core/span_type.hpp b/src/core/span_type.hpp
deleted file mode 100644
--- a/src/core/span_type.hpp
+++ /dev/null
@@ -1,110 +0,0 @@
-/*
- * This file is part of OpenTTD.
- * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
- * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
- */
-
-/** @file span_type.hpp Minimized implementation of C++20 std::span. */
-
-#ifndef CORE_SPAN_TYPE_HPP
-#define CORE_SPAN_TYPE_HPP
-
-/* This is a partial copy/paste from https://github.com/gsl-lite/gsl-lite/blob/master/include/gsl/gsl-lite.hpp */
-
-/* Template to check if a template variable defines size() and data(). */
-template <class, class = void>
-struct has_size_and_data : std::false_type{};
-template <class C>
-struct has_size_and_data
-<
-	C, std::void_t<
-		decltype(std::size(std::declval<C>())),
-		decltype(std::data(std::declval<C>()))>
-> : std::true_type{};
-
-/* Template to check if two elements are compatible. */
-template <class, class, class = void>
-struct is_compatible_element : std::false_type {};
-template <class C, class E>
-struct is_compatible_element
-<
-	C, E, std::void_t<
-		decltype(std::data(std::declval<C>())),
-		typename std::remove_pointer_t<decltype(std::data( std::declval<C&>()))>(*)[]>
-> : std::is_convertible<typename std::remove_pointer_t<decltype(std::data(std::declval<C&>()))>(*)[], E(*)[]>{};
-
-/* Template to check if a container is compatible. gsl-lite also includes is_array and is_std_array, but as we don't use them, they are omitted. */
-template <class C, class E>
-struct is_compatible_container : std::bool_constant
-<
-	has_size_and_data<C>::value
-	&& is_compatible_element<C, E>::value
->{};
-
-/**
- * A trimmed down version of what std::span will be in C++20.
- *
- * It is fully forwards compatible, so if this codebase switches to C++20,
- * all "span" instances can be replaced by "std::span" without loss of
- * functionality.
- *
- * Currently it only supports basic functionality:
- * - size() and friends
- * - begin() and friends
- *
- * It is meant to simplify function parameters, where we only want to walk
- * a continuous list.
- */
-template<class T>
-class span {
-public:
-	typedef T element_type;
-	typedef typename std::remove_cv< T >::type value_type;
-
-	typedef T &reference;
-	typedef T *pointer;
-	typedef const T &const_reference;
-	typedef const T *const_pointer;
-
-	typedef pointer iterator;
-	typedef const_pointer const_iterator;
-
-	typedef size_t size_type;
-	typedef std::ptrdiff_t difference_type;
-
-	constexpr span() noexcept : first(nullptr), last(nullptr) {}
-
-	constexpr span(pointer data_in, size_t size_in) : first(data_in), last(data_in + size_in) {}
-
-	template<class Container, typename std::enable_if<(is_compatible_container<Container, element_type>::value), int>::type = 0>
-	constexpr span(Container &list) noexcept : first(std::data(list)), last(std::data(list) + std::size(list)) {}
-	template<class Container, typename std::enable_if<(std::is_const<element_type>::value && is_compatible_container<Container, element_type>::value), int>::type = 0>
-	constexpr span(const Container &list) noexcept : first(std::data(list)), last(std::data(list) + std::size(list)) {}
-
-	constexpr size_t size() const noexcept { return static_cast<size_t>( last - first ); }
-	constexpr std::ptrdiff_t ssize() const noexcept { return static_cast<std::ptrdiff_t>( last - first ); }
-	constexpr bool empty() const noexcept { return this->size() == 0; }
-
-	constexpr iterator begin() const noexcept { return iterator(first); }
-	constexpr iterator end() const noexcept { return iterator(last); }
-
-	constexpr const_iterator cbegin() const noexcept { return const_iterator(first); }
-	constexpr const_iterator cend() const noexcept { return const_iterator(last); }
-
-	constexpr reference operator[](size_type idx) const { return first[idx]; }
-
-	constexpr pointer data() const noexcept { return first; }
-
-	constexpr span<element_type> subspan(size_t offset, size_t count)
-	{
-		assert(offset + count <= size());
-		return span(this->data() + offset, count);
-	}
-
-private:
-	pointer first;
-	pointer last;
-};
-
-#endif /* CORE_SPAN_TYPE_HPP */
diff --git a/src/misc/endian_buffer.hpp b/src/misc/endian_buffer.hpp
--- a/src/misc/endian_buffer.hpp
+++ b/src/misc/endian_buffer.hpp
@@ -11,7 +11,6 @@
 #define ENDIAN_BUFFER_HPP
 
 #include <string_view>
-#include "../core/span_type.hpp"
 #include "../core/bitmath_func.hpp"
 #include "../core/overflowsafe_type.hpp"
 
@@ -119,12 +118,12 @@ private:
  */
 class EndianBufferReader {
 	/** Reference to storage buffer. */
-	span<const byte> buffer;
+	std::span<const byte> buffer;
 	/** Current read position. */
 	size_t read_pos = 0;
 
 public:
-	EndianBufferReader(span<const byte> buffer) : buffer(buffer) {}
+	EndianBufferReader(std::span<const byte> buffer) : buffer(buffer) {}
 
 	void rewind() { this->read_pos = 0; }
 
@@ -155,7 +154,7 @@ public:
 	}
 
 	template <typename Tvalue>
-	static Tvalue ToValue(span<const byte> buffer)
+	static Tvalue ToValue(std::span<const byte> buffer)
 	{
 		Tvalue result{};
 		EndianBufferReader reader{ buffer };
diff --git a/src/news_gui.cpp b/src/news_gui.cpp
--- a/src/news_gui.cpp
+++ b/src/news_gui.cpp
@@ -586,7 +586,7 @@ private:
 	StringID GetCompanyMessageString() const
 	{
 		/* Company news with a face have a separate headline, so the normal message is shifted by two params */
-		CopyInDParam(span(this->ni->params.data() + 2, this->ni->params.size() - 2));
+		CopyInDParam(std::span(this->ni->params.data() + 2, this->ni->params.size() - 2));
 		return this->ni->params[1].data;
 	}
 
diff --git a/src/saveload/saveload.h b/src/saveload/saveload.h
--- a/src/saveload/saveload.h
+++ b/src/saveload/saveload.h
@@ -13,7 +13,6 @@
 #include "saveload_error.hpp"
 #include "../fileio_type.h"
 #include "../fios.h"
-#include "../core/span_type.hpp"
 
 /** SaveLoad versions
  * Previous savegame versions, the trunk revision where they were
@@ -480,13 +479,13 @@ struct ChunkHandler {
 using ChunkHandlerRef = std::reference_wrapper<const ChunkHandler>;
 
 /** A table of ChunkHandler entries. */
-using ChunkHandlerTable = span<const ChunkHandlerRef>;
+using ChunkHandlerTable = std::span<const ChunkHandlerRef>;
 
 /** A table of SaveLoad entries. */
-using SaveLoadTable = span<const struct SaveLoad>;
+using SaveLoadTable = std::span<const struct SaveLoad>;
 
 /** A table of SaveLoadCompat entries. */
-using SaveLoadCompatTable = span<const struct SaveLoadCompat>;
+using SaveLoadCompatTable = std::span<const struct SaveLoadCompat>;
 
 /** Handler for saving/loading an object to/from disk. */
 class SaveLoadHandler {
diff --git a/src/settings_internal.h b/src/settings_internal.h
--- a/src/settings_internal.h
+++ b/src/settings_internal.h
@@ -360,7 +360,7 @@ static constexpr const SettingDesc *GetS
 	return std::visit([](auto&& arg) -> const SettingDesc * { return &arg; }, desc);
 }
 
-typedef span<const SettingVariant> SettingTable;
+typedef std::span<const SettingVariant> SettingTable;
 
 const SettingDesc *GetSettingFromName(const std::string_view name);
 void GetSaveLoadFromSettingTable(SettingTable settings, std::vector<SaveLoad> &saveloads);
diff --git a/src/stdafx.h b/src/stdafx.h
--- a/src/stdafx.h
+++ b/src/stdafx.h
@@ -70,6 +70,7 @@
 #include <numeric>
 #include <optional>
 #include <set>
+#include <span>
 #include <stdexcept>
 #include <string>
 #include <type_traits>
diff --git a/src/string.cpp b/src/string.cpp
--- a/src/string.cpp
+++ b/src/string.cpp
@@ -85,7 +85,7 @@ char *strecpy(char *dst, const char *src
  * @param data Array to format
  * @return Converted string.
  */
-std::string FormatArrayAsHex(span<const byte> data)
+std::string FormatArrayAsHex(std::span<const byte> data)
 {
 	std::string str;
 	str.reserve(data.size() * 2 + 1);
diff --git a/src/string_func.h b/src/string_func.h
--- a/src/string_func.h
+++ b/src/string_func.h
@@ -15,12 +15,11 @@
 #include <iosfwd>
 
 #include "core/bitmath_func.hpp"
-#include "core/span_type.hpp"
 #include "string_type.h"
 
 char *strecpy(char *dst, const char *src, const char *last) NOACCESS(3);
 
-std::string FormatArrayAsHex(span<const byte> data);
+std::string FormatArrayAsHex(std::span<const byte> data);
 
 void StrMakeValidInPlace(char *str, const char *last, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK) NOACCESS(2);
 [[nodiscard]] std::string StrMakeValid(std::string_view str, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK);
diff --git a/src/strings.cpp b/src/strings.cpp
--- a/src/strings.cpp
+++ b/src/strings.cpp
@@ -155,7 +155,7 @@ void SetDParamMaxDigits(size_t n, uint c
  * Copy the parameters from the backup into the global string parameter array.
  * @param backup The backup to copy from.
  */
-void CopyInDParam(const span<const StringParameterBackup> backup)
+void CopyInDParam(const std::span<const StringParameterBackup> backup)
 {
 	for (size_t i = 0; i < backup.size(); i++) {
 		auto &value = backup[i];
diff --git a/src/strings_func.h b/src/strings_func.h
--- a/src/strings_func.h
+++ b/src/strings_func.h
@@ -14,7 +14,6 @@
 #include "string_type.h"
 #include "gfx_type.h"
 #include "core/bitmath_func.hpp"
-#include "core/span_type.hpp"
 #include "core/strong_typedef_type.hpp"
 #include "vehicle_type.h"
 
@@ -99,7 +98,7 @@ void SetDParamStr(size_t n, const char *
 void SetDParamStr(size_t n, const std::string &str);
 void SetDParamStr(size_t n, std::string &&str);
 
-void CopyInDParam(const span<const StringParameterBackup> backup);
+void CopyInDParam(const std::span<const StringParameterBackup> backup);
 void CopyOutDParam(std::vector<StringParameterBackup> &backup, size_t num);
 bool HaveDParamChanged(const std::vector<StringParameterBackup> &backup);
 
diff --git a/src/strings_internal.h b/src/strings_internal.h
--- a/src/strings_internal.h
+++ b/src/strings_internal.h
@@ -12,7 +12,6 @@
 
 #include "strings_func.h"
 #include "string_func.h"
-#include "core/span_type.hpp"
 
 /** The data required to format and validate a single parameter of a string. */
 struct StringParameter {
@@ -25,12 +24,12 @@ struct StringParameter {
 class StringParameters {
 protected:
 	StringParameters *parent = nullptr; ///< If not nullptr, this instance references data from this parent instance.
-	span<StringParameter> parameters = {}; ///< Array with the actual parameters.
+	std::span<StringParameter> parameters = {}; ///< Array with the actual parameters.
 
 	size_t offset = 0; ///< Current offset in the parameters span.
 	char32_t next_type = 0; ///< The type of the next data that is retrieved.
 
-	StringParameters(span<StringParameter> parameters = {}) :
+	StringParameters(std::span<StringParameter> parameters = {}) :
 		parameters(parameters)
 	{}
 
@@ -211,7 +210,7 @@ class ArrayStringParameters : public Str
 public:
 	ArrayStringParameters()
 	{
-		this->parameters = span(params.data(), params.size());
+		this->parameters = std::span(params.data(), params.size());
 	}
 
 	ArrayStringParameters(ArrayStringParameters&& other) noexcept
@@ -224,7 +223,7 @@ public:
 		this->offset = other.offset;
 		this->next_type = other.next_type;
 		this->params = std::move(other.params);
-		this->parameters = span(params.data(), params.size());
+		this->parameters = std::span(params.data(), params.size());
 		return *this;
 	}
 
diff --git a/src/survey.cpp b/src/survey.cpp
--- a/src/survey.cpp
+++ b/src/survey.cpp
@@ -250,9 +250,9 @@ void SurveyConfiguration(nlohmann::json 
 		survey["graphics_set"] = fmt::format("{}.{}", BaseGraphics::GetUsedSet()->name, BaseGraphics::GetUsedSet()->version);
 		const GRFConfig *extra_cfg = BaseGraphics::GetUsedSet()->GetExtraConfig();
 		if (extra_cfg != nullptr && extra_cfg->num_params > 0) {
-			survey["graphics_set_parameters"] = span<const uint32_t>(extra_cfg->param.data(), extra_cfg->num_params);
+			survey["graphics_set_parameters"] = std::span<const uint32_t>(extra_cfg->param.data(), extra_cfg->num_params);
 		} else {
-			survey["graphics_set_parameters"] = span<const uint32_t>();
+			survey["graphics_set_parameters"] = std::span<const uint32_t>();
 		}
 	}
 	if (BaseMusic::GetUsedSet() != nullptr) {
@@ -344,7 +344,7 @@ void SurveyGrfs(nlohmann::json &survey)
 		if ((c->palette & GRFP_BLT_MASK) == GRFP_BLT_32BPP) grf["blitter"] = "32bpp";
 
 		grf["is_static"] = HasBit(c->flags, GCF_STATIC);
-		grf["parameters"] = span<const uint32_t>(c->param.data(), c->num_params);
+		grf["parameters"] = std::span<const uint32_t>(c->param.data(), c->num_params);
 	}
 }