3dc1f759e6
This patch removes code which is guarded by `_LIBCPP_STD_VER` and `_LIBCPP_CXX03_LANG`. This is part of https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc.
47 lines
1.6 KiB
C++
47 lines
1.6 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP___CXX03___RANDOM_GENERATE_CANONICAL_H
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#define _LIBCPP___CXX03___RANDOM_GENERATE_CANONICAL_H
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#include <__cxx03/__config>
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#include <__cxx03/__random/log2.h>
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#include <__cxx03/cstdint>
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#include <__cxx03/limits>
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#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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# pragma GCC system_header
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#endif
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_LIBCPP_PUSH_MACROS
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#include <__cxx03/__undef_macros>
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_LIBCPP_BEGIN_NAMESPACE_STD
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// generate_canonical
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template <class _RealType, size_t __bits, class _URNG>
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_LIBCPP_HIDE_FROM_ABI _RealType generate_canonical(_URNG& __g) {
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const size_t __dt = numeric_limits<_RealType>::digits;
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const size_t __b = __dt < __bits ? __dt : __bits;
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const size_t __log_r = __log2<uint64_t, _URNG::_Max - _URNG::_Min + uint64_t(1)>::value;
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const size_t __k = __b / __log_r + (__b % __log_r != 0) + (__b == 0);
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const _RealType __rp = static_cast<_RealType>(_URNG::max() - _URNG::min()) + _RealType(1);
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_RealType __base = __rp;
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_RealType __sp = __g() - _URNG::min();
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for (size_t __i = 1; __i < __k; ++__i, __base *= __rp)
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__sp += (__g() - _URNG::min()) * __base;
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return __sp / __base;
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}
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_LIBCPP_END_NAMESPACE_STD
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_LIBCPP_POP_MACROS
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#endif // _LIBCPP___CXX03___RANDOM_GENERATE_CANONICAL_H
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