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Diffstat (limited to 'third_party/abseil_cpp/absl/random/internal/iostream_state_saver.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/random/internal/iostream_state_saver.h | 245 |
1 files changed, 0 insertions, 245 deletions
diff --git a/third_party/abseil_cpp/absl/random/internal/iostream_state_saver.h b/third_party/abseil_cpp/absl/random/internal/iostream_state_saver.h deleted file mode 100644 index e6e242ee1e..0000000000 --- a/third_party/abseil_cpp/absl/random/internal/iostream_state_saver.h +++ /dev/null @@ -1,245 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -#ifndef ABSL_RANDOM_INTERNAL_IOSTREAM_STATE_SAVER_H_ -#define ABSL_RANDOM_INTERNAL_IOSTREAM_STATE_SAVER_H_ - -#include <cmath> -#include <iostream> -#include <limits> -#include <type_traits> - -#include "absl/meta/type_traits.h" -#include "absl/numeric/int128.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace random_internal { - -// The null_state_saver does nothing. -template <typename T> -class null_state_saver { - public: - using stream_type = T; - using flags_type = std::ios_base::fmtflags; - - null_state_saver(T&, flags_type) {} - ~null_state_saver() {} -}; - -// ostream_state_saver is a RAII object to save and restore the common -// basic_ostream flags used when implementing `operator <<()` on any of -// the absl random distributions. -template <typename OStream> -class ostream_state_saver { - public: - using ostream_type = OStream; - using flags_type = std::ios_base::fmtflags; - using fill_type = typename ostream_type::char_type; - using precision_type = std::streamsize; - - ostream_state_saver(ostream_type& os, // NOLINT(runtime/references) - flags_type flags, fill_type fill) - : os_(os), - flags_(os.flags(flags)), - fill_(os.fill(fill)), - precision_(os.precision()) { - // Save state in initialized variables. - } - - ~ostream_state_saver() { - // Restore saved state. - os_.precision(precision_); - os_.fill(fill_); - os_.flags(flags_); - } - - private: - ostream_type& os_; - const flags_type flags_; - const fill_type fill_; - const precision_type precision_; -}; - -#if defined(__NDK_MAJOR__) && __NDK_MAJOR__ < 16 -#define ABSL_RANDOM_INTERNAL_IOSTREAM_HEXFLOAT 1 -#else -#define ABSL_RANDOM_INTERNAL_IOSTREAM_HEXFLOAT 0 -#endif - -template <typename CharT, typename Traits> -ostream_state_saver<std::basic_ostream<CharT, Traits>> make_ostream_state_saver( - std::basic_ostream<CharT, Traits>& os, // NOLINT(runtime/references) - std::ios_base::fmtflags flags = std::ios_base::dec | std::ios_base::left | -#if ABSL_RANDOM_INTERNAL_IOSTREAM_HEXFLOAT - std::ios_base::fixed | -#endif - std::ios_base::scientific) { - using result_type = ostream_state_saver<std::basic_ostream<CharT, Traits>>; - return result_type(os, flags, os.widen(' ')); -} - -template <typename T> -typename absl::enable_if_t<!std::is_base_of<std::ios_base, T>::value, - null_state_saver<T>> -make_ostream_state_saver(T& is, // NOLINT(runtime/references) - std::ios_base::fmtflags flags = std::ios_base::dec) { - std::cerr << "null_state_saver"; - using result_type = null_state_saver<T>; - return result_type(is, flags); -} - -// stream_precision_helper<type>::kPrecision returns the base 10 precision -// required to stream and reconstruct a real type exact binary value through -// a binary->decimal->binary transition. -template <typename T> -struct stream_precision_helper { - // max_digits10 may be 0 on MSVC; if so, use digits10 + 3. - static constexpr int kPrecision = - (std::numeric_limits<T>::max_digits10 > std::numeric_limits<T>::digits10) - ? std::numeric_limits<T>::max_digits10 - : (std::numeric_limits<T>::digits10 + 3); -}; - -template <> -struct stream_precision_helper<float> { - static constexpr int kPrecision = 9; -}; -template <> -struct stream_precision_helper<double> { - static constexpr int kPrecision = 17; -}; -template <> -struct stream_precision_helper<long double> { - static constexpr int kPrecision = 36; // assuming fp128 -}; - -// istream_state_saver is a RAII object to save and restore the common -// std::basic_istream<> flags used when implementing `operator >>()` on any of -// the absl random distributions. -template <typename IStream> -class istream_state_saver { - public: - using istream_type = IStream; - using flags_type = std::ios_base::fmtflags; - - istream_state_saver(istream_type& is, // NOLINT(runtime/references) - flags_type flags) - : is_(is), flags_(is.flags(flags)) {} - - ~istream_state_saver() { is_.flags(flags_); } - - private: - istream_type& is_; - flags_type flags_; -}; - -template <typename CharT, typename Traits> -istream_state_saver<std::basic_istream<CharT, Traits>> make_istream_state_saver( - std::basic_istream<CharT, Traits>& is, // NOLINT(runtime/references) - std::ios_base::fmtflags flags = std::ios_base::dec | - std::ios_base::scientific | - std::ios_base::skipws) { - using result_type = istream_state_saver<std::basic_istream<CharT, Traits>>; - return result_type(is, flags); -} - -template <typename T> -typename absl::enable_if_t<!std::is_base_of<std::ios_base, T>::value, - null_state_saver<T>> -make_istream_state_saver(T& is, // NOLINT(runtime/references) - std::ios_base::fmtflags flags = std::ios_base::dec) { - using result_type = null_state_saver<T>; - return result_type(is, flags); -} - -// stream_format_type<T> is a helper struct to convert types which -// basic_iostream cannot output as decimal numbers into types which -// basic_iostream can output as decimal numbers. Specifically: -// * signed/unsigned char-width types are converted to int. -// * TODO(lar): __int128 => uint128, except there is no operator << yet. -// -template <typename T> -struct stream_format_type - : public std::conditional<(sizeof(T) == sizeof(char)), int, T> {}; - -// stream_u128_helper allows us to write out either absl::uint128 or -// __uint128_t types in the same way, which enables their use as internal -// state of PRNG engines. -template <typename T> -struct stream_u128_helper; - -template <> -struct stream_u128_helper<absl::uint128> { - template <typename IStream> - inline absl::uint128 read(IStream& in) { - uint64_t h = 0; - uint64_t l = 0; - in >> h >> l; - return absl::MakeUint128(h, l); - } - - template <typename OStream> - inline void write(absl::uint128 val, OStream& out) { - uint64_t h = absl::Uint128High64(val); - uint64_t l = absl::Uint128Low64(val); - out << h << out.fill() << l; - } -}; - -#ifdef ABSL_HAVE_INTRINSIC_INT128 -template <> -struct stream_u128_helper<__uint128_t> { - template <typename IStream> - inline __uint128_t read(IStream& in) { - uint64_t h = 0; - uint64_t l = 0; - in >> h >> l; - return (static_cast<__uint128_t>(h) << 64) | l; - } - - template <typename OStream> - inline void write(__uint128_t val, OStream& out) { - uint64_t h = static_cast<uint64_t>(val >> 64u); - uint64_t l = static_cast<uint64_t>(val); - out << h << out.fill() << l; - } -}; -#endif - -template <typename FloatType, typename IStream> -inline FloatType read_floating_point(IStream& is) { - static_assert(std::is_floating_point<FloatType>::value, ""); - FloatType dest; - is >> dest; - // Parsing a double value may report a subnormal value as an error - // despite being able to represent it. - // See https://stackoverflow.com/q/52410931/3286653 - // It may also report an underflow when parsing DOUBLE_MIN as an - // ERANGE error, as the parsed value may be smaller than DOUBLE_MIN - // and rounded up. - // See: https://stackoverflow.com/q/42005462 - if (is.fail() && - (std::fabs(dest) == (std::numeric_limits<FloatType>::min)() || - std::fpclassify(dest) == FP_SUBNORMAL)) { - is.clear(is.rdstate() & (~std::ios_base::failbit)); - } - return dest; -} - -} // namespace random_internal -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_RANDOM_INTERNAL_IOSTREAM_STATE_SAVER_H_ |