--- /dev/null
+// align implementation -*- C++ -*-
+
+// Copyright (C) 2014-2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library 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; either version 3, or (at your option)
+// any later version.
+
+// This library 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.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file bits/align.h
+ * This is an internal header file, included by other library headers.
+ * Do not attempt to use it directly. @headername{memory}
+ */
+
+#ifndef _GLIBCXX_ALIGN_H
+#define _GLIBCXX_ALIGN_H 1
+
+#include <bits/c++config.h>
+
+#include <bit> // std::has_single_bit
+#include <stdint.h> // uintptr_t
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+/**
+ * @brief Fit aligned storage in buffer.
+ * @ingroup memory
+ *
+ * This function tries to fit @a __size bytes of storage with alignment
+ * @a __align into the buffer @a __ptr of size @a __space bytes. If such
+ * a buffer fits then @a __ptr is changed to point to the first byte of the
+ * aligned storage and @a __space is reduced by the bytes used for alignment.
+ *
+ * C++11 20.6.5 [ptr.align]
+ *
+ * @param __align A fundamental or extended alignment value.
+ * @param __size Size of the aligned storage required.
+ * @param __ptr Pointer to a buffer of @a __space bytes.
+ * @param __space Size of the buffer pointed to by @a __ptr.
+ * @return the updated pointer if the aligned storage fits, otherwise nullptr.
+ *
+ */
+inline void*
+align(size_t __align, size_t __size, void*& __ptr, size_t& __space) noexcept
+{
+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+ const auto __intptr = reinterpret_cast<uintptr_t>(__ptr);
+#else
+ // Cannot use std::uintptr_t so assume that std::size_t can be used instead.
+ static_assert(sizeof(size_t) >= sizeof(void*),
+ "std::size_t must be a suitable substitute for std::uintptr_t");
+ const auto __intptr = reinterpret_cast<unsigned long long>(__ptr);
+#endif
+ const auto __aligned = (__intptr - 1u + __align) & -__align;
+ const auto __diff = __aligned - __intptr;
+ if ((__size + __diff) > __space)
+ return nullptr;
+ else
+ {
+ __space -= __diff;
+ return __ptr = reinterpret_cast<void*>(__aligned);
+ }
+}
+
+#if __cplusplus > 201703L
+#define __cpp_lib_assume_aligned 201811L
+ /** @brief Inform the compiler that a pointer is aligned.
+ *
+ * @tparam _Align An alignment value (i.e. a power of two)
+ * @tparam _Tp An object type
+ * @param __ptr A pointer that is aligned to _Align
+ * @ingroup memory
+ */
+ template<size_t _Align, class _Tp>
+ [[nodiscard,__gnu__::__always_inline__]]
+ constexpr _Tp* assume_aligned(_Tp* __ptr)
+ {
+ static_assert(std::has_single_bit(_Align));
+ _GLIBCXX_DEBUG_ASSERT((std::uintptr_t)__ptr % _Align == 0);
+ return static_cast<_Tp*>(__builtin_assume_aligned(__ptr, _Align));
+ }
+#endif // C++2a
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+
+#endif /* _GLIBCXX_ALIGN_H */
*/
#include <bits/stl_algobase.h>
+#include <bits/align.h>
#include <bits/allocator.h>
#include <bits/stl_construct.h>
#include <bits/stl_uninitialized.h>
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
-/**
- * @brief Fit aligned storage in buffer.
- * @ingroup memory
- *
- * This function tries to fit @a __size bytes of storage with alignment
- * @a __align into the buffer @a __ptr of size @a __space bytes. If such
- * a buffer fits then @a __ptr is changed to point to the first byte of the
- * aligned storage and @a __space is reduced by the bytes used for alignment.
- *
- * C++11 20.6.5 [ptr.align]
- *
- * @param __align A fundamental or extended alignment value.
- * @param __size Size of the aligned storage required.
- * @param __ptr Pointer to a buffer of @a __space bytes.
- * @param __space Size of the buffer pointed to by @a __ptr.
- * @return the updated pointer if the aligned storage fits, otherwise nullptr.
- *
- */
-inline void*
-align(size_t __align, size_t __size, void*& __ptr, size_t& __space) noexcept
-{
-#ifdef _GLIBCXX_USE_C99_STDINT_TR1
- const auto __intptr = reinterpret_cast<uintptr_t>(__ptr);
-#else
- // Cannot use std::uintptr_t so assume that std::size_t can be used instead.
- static_assert(sizeof(size_t) >= sizeof(void*),
- "std::size_t must be a suitable substitute for std::uintptr_t");
- const auto __intptr = reinterpret_cast<unsigned long long>(__ptr);
-#endif
- const auto __aligned = (__intptr - 1u + __align) & -__align;
- const auto __diff = __aligned - __intptr;
- if ((__size + __diff) > __space)
- return nullptr;
- else
- {
- __space -= __diff;
- return __ptr = reinterpret_cast<void*>(__aligned);
- }
-}
-
/** @defgroup ptr_safety Pointer Safety and Garbage Collection
* @ingroup memory
*
get_pointer_safety() noexcept { return pointer_safety::relaxed; }
// @}
-#if __cplusplus > 201703L
-#define __cpp_lib_assume_aligned 201811L
- /** @brief Inform the compiler that a pointer is aligned.
- *
- * @tparam _Align An alignment value (i.e. a power of two)
- * @tparam _Tp An object type
- * @param __ptr A pointer that is aligned to _Align
- * @ingroup memory
- */
- template<size_t _Align, class _Tp>
- [[nodiscard,__gnu__::__always_inline__]]
- constexpr _Tp* assume_aligned(_Tp* __ptr)
- {
- static_assert(std::has_single_bit(_Align));
- _GLIBCXX_DEBUG_ASSERT((std::uintptr_t)__ptr % _Align == 0);
- return static_cast<_Tp*>(__builtin_assume_aligned(__ptr, _Align));
- }
-#endif // C++2a
-
#if __cplusplus > 201703L
template<typename _Tp>
struct __is_pair : false_type { };
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