From e59cf7b09e7388d369e8d2bf73501cde79c28708 Mon Sep 17 00:00:00 2001
From: Toni Uhlig <matzeton@googlemail.com>
Date: Thu, 8 Apr 2021 16:43:58 +0200
Subject: Squashed 'EASTL/' content from commit fad5471

git-subtree-dir: EASTL
git-subtree-split: fad54717f8e4ebb13b20095da7efd07a53af0f10
---
 include/EASTL/bonus/adaptors.h | 88 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 include/EASTL/bonus/adaptors.h

(limited to 'include/EASTL/bonus/adaptors.h')

diff --git a/include/EASTL/bonus/adaptors.h b/include/EASTL/bonus/adaptors.h
new file mode 100644
index 0000000..423cacd
--- /dev/null
+++ b/include/EASTL/bonus/adaptors.h
@@ -0,0 +1,88 @@
+/////////////////////////////////////////////////////////////////////////////
+// Copyright (c) Electronic Arts Inc. All rights reserved.
+/////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+
+
+#ifndef EASTL_ADAPTORS_H
+#define EASTL_ADAPTORS_H
+
+
+#include <EASTL/internal/config.h>
+#include <EASTL/internal/move_help.h>
+#include <EASTL/type_traits.h>
+#include <EASTL/iterator.h>
+
+#if defined(EA_PRAGMA_ONCE_SUPPORTED)
+	#pragma once // Some compilers (e.g. VC++) benefit significantly from using this. We've measured 3-4% build speed improvements in apps as a result.
+#endif
+
+EA_DISABLE_VC_WARNING(4512 4626)
+#if defined(_MSC_VER) && (_MSC_VER >= 1900) // VS2015+
+	EA_DISABLE_VC_WARNING(5027) // move assignment operator was implicitly defined as deleted
+#endif
+
+
+namespace eastl
+{
+	/// reverse
+	///
+	/// This adaptor allows reverse iteration of a container in ranged base for-loops.
+	///
+	/// for (auto& i : reverse(c)) { ... }
+	///
+	template <typename Container>
+	struct reverse_wrapper
+	{
+		template <typename C>
+		reverse_wrapper(C&& c)
+			: mContainer(eastl::forward<C>(c))
+		{
+			/**
+			 * NOTE:
+			 *
+			 * Due to reference collapsing rules of universal references Container type is either
+			 *
+			 * const C&  if the input is a const lvalue
+			 * C&        if the input is a non-const lvalue
+			 * C         if the input is an rvalue
+			 * const C   if the input is a const rvalue thus the object will have to be copied and the copy-ctor will be called
+			 *
+			 *
+			 * Thus we either move the whole container into this object or take a reference to the lvalue avoiding the copy.
+			 * The static_assert below ensures this.
+			 */
+			static_assert(eastl::is_same_v<C, Container>, "Reference collapsed deduced type must be the same as the deduced Container type!");
+		}
+
+		Container mContainer;
+	};
+
+	template <typename Container>
+	auto begin(const reverse_wrapper<Container>& w) -> decltype(eastl::rbegin(w.mContainer))
+	{
+		return eastl::rbegin(w.mContainer);
+	}
+
+	template <typename Container>
+	auto end(const reverse_wrapper<Container>& w) -> decltype(eastl::rend(w.mContainer))
+	{
+		return eastl::rend(w.mContainer);
+	}
+
+	template <typename Container>
+	reverse_wrapper<Container> reverse(Container&& c)
+	{
+		return reverse_wrapper<Container>(eastl::forward<Container>(c));
+	}
+
+} // namespace eastl
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1900) // VS2015+
+	EA_RESTORE_VC_WARNING()
+#endif
+EA_RESTORE_VC_WARNING()
+
+#endif // Header include guard
-- 
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