Export of internal Abseil changes.

--
7a6ff16a85beb730c172d5d25cf1b5e1be885c56 by Laramie Leavitt <lar@google.com>:

Internal change.

PiperOrigin-RevId: 254454546

--
ff8f9bafaefc26d451f576ea4a06d150aed63f6f by Andy Soffer <asoffer@google.com>:

Internal changes

PiperOrigin-RevId: 254451562

--
deefc5b651b479ce36f0b4ef203e119c0c8936f2 by CJ Johnson <johnsoncj@google.com>:

Account for subtracting unsigned values from the size of InlinedVector

PiperOrigin-RevId: 254450625

--
3c677316a27bcadc17e41957c809ca472d5fef14 by Andy Soffer <asoffer@google.com>:

Add C++17's std::make_from_tuple to absl/utility/utility.h

PiperOrigin-RevId: 254411573

--
4ee3536a918830eeec402a28fc31a62c7c90b940 by CJ Johnson <johnsoncj@google.com>:

Adds benchmark for the rest of the InlinedVector public API

PiperOrigin-RevId: 254408378

--
e5a21a00700ee83498ff1efbf649169756463ee4 by CJ Johnson <johnsoncj@google.com>:

Updates the definition of InlinedVector::shrink_to_fit() to be exception safe and adds exception safety tests for it.

PiperOrigin-RevId: 254401387

--
2ea82e72b86d82d78b4e4712a63a55981b53c64b by Laramie Leavitt <lar@google.com>:

Use absl::InsecureBitGen in place of std::mt19937
in tests absl/random/...distribution_test.cc

PiperOrigin-RevId: 254289444

--
fa099e02c413a7ffda732415e8105cad26a90337 by Andy Soffer <asoffer@google.com>:

Internal changes

PiperOrigin-RevId: 254286334

--
ce34b7f36933b30cfa35b9c9a5697a792b5666e4 by Andy Soffer <asoffer@google.com>:

Internal changes

PiperOrigin-RevId: 254273059

--
6f9c473da7c2090c2e85a37c5f00622e8a912a89 by Jorg Brown <jorg@google.com>:

Change absl::container_internal::CompressedTuple to instantiate its
internal Storage class with the name of the type it's holding, rather
than the name of the Tuple.  This is not an externally-visible change,
other than less compiler memory is used and less debug information is
generated.

PiperOrigin-RevId: 254269285

--
8bd3c186bf2fc0c55d8a2dd6f28a5327502c9fba by Andy Soffer <asoffer@google.com>:

Adding short-hand IntervalClosed for IntervalClosedClosed and IntervalOpen for
IntervalOpenOpen.

PiperOrigin-RevId: 254252419

--
ea957f99b6a04fccd42aa05605605f3b44b1ecfd by Abseil Team <absl-team@google.com>:

Do not directly use __SIZEOF_INT128__.

In order to avoid linker errors when building with clang-cl (__fixunsdfti, __udivti3 and __fixunssfti are undefined), this CL uses ABSL_HAVE_INTRINSIC_INT128 which is not defined for clang-cl.

PiperOrigin-RevId: 254250739

--
89ab385cd26b34d64130bce856253aaba96d2345 by Andy Soffer <asoffer@google.com>:

Internal changes

PiperOrigin-RevId: 254242321

--
cffc793d93eca6d6bdf7de733847b6ab4a255ae9 by CJ Johnson <johnsoncj@google.com>:

Adds benchmark for InlinedVector::reserve(size_type)

PiperOrigin-RevId: 254199226

--
c90c7a9fa3c8f0c9d5114036979548b055ea2f2a by Gennadiy Rozental <rogeeff@google.com>:

Import of CCTZ from GitHub.

PiperOrigin-RevId: 254072387

--
c4c388beae016c9570ab54ffa1d52660e4a85b7b by Laramie Leavitt <lar@google.com>:

Internal cleanup.

PiperOrigin-RevId: 254062381

--
d3c992e221cc74e5372d0c8fa410170b6a43c062 by Tom Manshreck <shreck@google.com>:

Update distributions.h to Abseil standards

PiperOrigin-RevId: 254054946

--
d15ad0035c34ef11b14fadc5a4a2d3ec415f5518 by CJ Johnson <johnsoncj@google.com>:

Removes functions with only one caller from the implementation details of InlinedVector by manually inlining the definitions

PiperOrigin-RevId: 254005427

--
2f37e807efc3a8ef1f4b539bdd379917d4151520 by Andy Soffer <asoffer@google.com>:

Initial release of Abseil Random

PiperOrigin-RevId: 253999861

--
24ed1694b6430791d781ed533a8f8ccf6cac5856 by CJ Johnson <johnsoncj@google.com>:

Updates the definition of InlinedVector::assign(...)/InlinedVector::operator=(...) to new, exception-safe implementations with exception safety tests to boot

PiperOrigin-RevId: 253993691

--
5613d95f5a7e34a535cfaeadce801441e990843e by CJ Johnson <johnsoncj@google.com>:

Adds benchmarks for InlinedVector::shrink_to_fit()

PiperOrigin-RevId: 253989647

--
2a96ddfdac40bbb8cb6a7f1aeab90917067c6e63 by Abseil Team <absl-team@google.com>:

Initial release of Abseil Random

PiperOrigin-RevId: 253927497

--
bf1aff8fc9ffa921ad74643e9525ecf25b0d8dc1 by Andy Soffer <asoffer@google.com>:

Initial release of Abseil Random

PiperOrigin-RevId: 253920512

--
bfc03f4a3dcda3cf3a4b84bdb84cda24e3394f41 by Laramie Leavitt <lar@google.com>:

Internal change.

PiperOrigin-RevId: 253886486

--
05036cfcc078ca7c5f581a00dfb0daed568cbb69 by Eric Fiselier <ericwf@google.com>:

Don't include `winsock2.h` because it drags in `windows.h` and friends,
and they define awful macros like OPAQUE, ERROR, and more. This has the
potential to break abseil users.

Instead we only forward declare `timeval` and require Windows users
include `winsock2.h` themselves. This is both inconsistent and poor QoI, but so
including 'windows.h' is bad too.

PiperOrigin-RevId: 253852615
GitOrigin-RevId: 7a6ff16a85beb730c172d5d25cf1b5e1be885c56
Change-Id: Icd6aff87da26f29ec8915da856f051129987cef6

1 files changed, 243 insertions, 0 deletions

diff --git a/absl/random/internal/iostream_state_saver.h b/absl/random/internal/iostream_state_saver.h
new file mode 100644
index 00000000..df88fa76
--- /dev/null
+++ b/absl/random/internal/iostream_state_saver.h
@@ -0,0 +1,243 @@
+// 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 {
+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 = Uint128High64(val);
+    uint64_t l = 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
+}  // namespace absl
+
+#endif  // ABSL_RANDOM_INTERNAL_IOSTREAM_STATE_SAVER_H_