Export of internal Abseil changes.

--
6befc69900cd77b5af55d1235b2c74dbeb37fbeb by Alex Strelnikov <strel@google.com>:

move ExtendedParsedFormat

PiperOrigin-RevId: 202336028

--
3adf2a6358189b28e9bdf982c4fd3110e24fb84b by Alex Strelnikov <strel@google.com>:

Internal change.

PiperOrigin-RevId: 202330527

--
8fdd1e8aee74992f5d4f3ab79739e6272feca7a8 by Alex Strelnikov <strel@google.com>:

move ExtendedParsedFormat

PiperOrigin-RevId: 202317418

--
c618725b2320d5c4292ea479b877c848ccdf2e6b by Alex Strelnikov <strel@google.com>:

Release strings:numbers_benchmark

PiperOrigin-RevId: 202297686

--
7c9f6132034a5a32160f56ca0dd0a4edcd476928 by Matt Kulukundis <kfm@google.com>:

Internal change

PiperOrigin-RevId: 202230893

--
bf1a0e1724e87e4fb55165997562efa9c8d081c5 by Juemin Yang <jueminyang@google.com>:

move ExtendedParsedFormat

PiperOrigin-RevId: 202199857
GitOrigin-RevId: 6befc69900cd77b5af55d1235b2c74dbeb37fbeb
Change-Id: Iafe46260e141de9f34b130b9d968a0ea542151d1

3 files changed, 276 insertions, 2 deletions

diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel
index 17831c20..3b1e0675 100644
--- a/absl/strings/BUILD.bazel
+++ b/absl/strings/BUILD.bazel
@@ -409,6 +409,19 @@ cc_test(
 )
 
 cc_test(
+    name = "numbers_benchmark",
+    srcs = ["numbers_benchmark.cc"],
+    copts = ABSL_TEST_COPTS,
+    tags = ["benchmark"],
+    visibility = ["//visibility:private"],
+    deps = [
+        ":strings",
+        "//absl/base",
+        "@com_github_google_benchmark//:benchmark_main",
+    ],
+)
+
+cc_test(
     name = "strip_test",
     size = "small",
     srcs = ["strip_test.cc"],
diff --git a/absl/strings/numbers_benchmark.cc b/absl/strings/numbers_benchmark.cc
new file mode 100644
index 00000000..8ef650b9
--- /dev/null
+++ b/absl/strings/numbers_benchmark.cc
@@ -0,0 +1,263 @@
+// Copyright 2018 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
+//
+//      http://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.
+
+#include <cstdint>
+#include <random>
+#include <string>
+#include <type_traits>
+#include <vector>
+
+#include "benchmark/benchmark.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/strings/numbers.h"
+
+namespace {
+
+template <typename T>
+void BM_FastIntToBuffer(benchmark::State& state) {
+  const int inc = state.range(0);
+  char buf[absl::numbers_internal::kFastToBufferSize];
+  // Use the unsigned type to increment to take advantage of well-defined
+  // modular arithmetic.
+  typename std::make_unsigned<T>::type x = 0;
+  for (auto _ : state) {
+    absl::numbers_internal::FastIntToBuffer(static_cast<T>(x), buf);
+    x += inc;
+  }
+}
+BENCHMARK_TEMPLATE(BM_FastIntToBuffer, int32_t)->Range(0, 1 << 15);
+BENCHMARK_TEMPLATE(BM_FastIntToBuffer, int64_t)->Range(0, 1 << 30);
+
+// Creates an integer that would be printed as `num_digits` repeated 7s in the
+// given `base`. `base` must be greater than or equal to 8.
+int64_t RepeatedSevens(int num_digits, int base) {
+  ABSL_RAW_CHECK(base >= 8, "");
+  int64_t num = 7;
+  while (--num_digits) num = base * num + 7;
+  return num;
+}
+
+void BM_safe_strto32_string(benchmark::State& state) {
+  const int digits = state.range(0);
+  const int base = state.range(1);
+  std::string str(digits, '7');  // valid in octal, decimal and hex
+  int32_t value = 0;
+  for (auto _ : state) {
+    benchmark::DoNotOptimize(
+        absl::numbers_internal::safe_strto32_base(str, &value, base));
+  }
+  ABSL_RAW_CHECK(value == RepeatedSevens(digits, base), "");
+}
+BENCHMARK(BM_safe_strto32_string)
+    ->ArgPair(1, 8)
+    ->ArgPair(1, 10)
+    ->ArgPair(1, 16)
+    ->ArgPair(2, 8)
+    ->ArgPair(2, 10)
+    ->ArgPair(2, 16)
+    ->ArgPair(4, 8)
+    ->ArgPair(4, 10)
+    ->ArgPair(4, 16)
+    ->ArgPair(8, 8)
+    ->ArgPair(8, 10)
+    ->ArgPair(8, 16)
+    ->ArgPair(10, 8)
+    ->ArgPair(9, 10);
+
+void BM_safe_strto64_string(benchmark::State& state) {
+  const int digits = state.range(0);
+  const int base = state.range(1);
+  std::string str(digits, '7');  // valid in octal, decimal and hex
+  int64_t value = 0;
+  for (auto _ : state) {
+    benchmark::DoNotOptimize(
+        absl::numbers_internal::safe_strto64_base(str, &value, base));
+  }
+  ABSL_RAW_CHECK(value == RepeatedSevens(digits, base), "");
+}
+BENCHMARK(BM_safe_strto64_string)
+    ->ArgPair(1, 8)
+    ->ArgPair(1, 10)
+    ->ArgPair(1, 16)
+    ->ArgPair(2, 8)
+    ->ArgPair(2, 10)
+    ->ArgPair(2, 16)
+    ->ArgPair(4, 8)
+    ->ArgPair(4, 10)
+    ->ArgPair(4, 16)
+    ->ArgPair(8, 8)
+    ->ArgPair(8, 10)
+    ->ArgPair(8, 16)
+    ->ArgPair(16, 8)
+    ->ArgPair(16, 10)
+    ->ArgPair(16, 16);
+
+void BM_safe_strtou32_string(benchmark::State& state) {
+  const int digits = state.range(0);
+  const int base = state.range(1);
+  std::string str(digits, '7');  // valid in octal, decimal and hex
+  uint32_t value = 0;
+  for (auto _ : state) {
+    benchmark::DoNotOptimize(
+        absl::numbers_internal::safe_strtou32_base(str, &value, base));
+  }
+  ABSL_RAW_CHECK(value == RepeatedSevens(digits, base), "");
+}
+BENCHMARK(BM_safe_strtou32_string)
+    ->ArgPair(1, 8)
+    ->ArgPair(1, 10)
+    ->ArgPair(1, 16)
+    ->ArgPair(2, 8)
+    ->ArgPair(2, 10)
+    ->ArgPair(2, 16)
+    ->ArgPair(4, 8)
+    ->ArgPair(4, 10)
+    ->ArgPair(4, 16)
+    ->ArgPair(8, 8)
+    ->ArgPair(8, 10)
+    ->ArgPair(8, 16)
+    ->ArgPair(10, 8)
+    ->ArgPair(9, 10);
+
+void BM_safe_strtou64_string(benchmark::State& state) {
+  const int digits = state.range(0);
+  const int base = state.range(1);
+  std::string str(digits, '7');  // valid in octal, decimal and hex
+  uint64_t value = 0;
+  for (auto _ : state) {
+    benchmark::DoNotOptimize(
+        absl::numbers_internal::safe_strtou64_base(str, &value, base));
+  }
+  ABSL_RAW_CHECK(value == RepeatedSevens(digits, base), "");
+}
+BENCHMARK(BM_safe_strtou64_string)
+    ->ArgPair(1, 8)
+    ->ArgPair(1, 10)
+    ->ArgPair(1, 16)
+    ->ArgPair(2, 8)
+    ->ArgPair(2, 10)
+    ->ArgPair(2, 16)
+    ->ArgPair(4, 8)
+    ->ArgPair(4, 10)
+    ->ArgPair(4, 16)
+    ->ArgPair(8, 8)
+    ->ArgPair(8, 10)
+    ->ArgPair(8, 16)
+    ->ArgPair(16, 8)
+    ->ArgPair(16, 10)
+    ->ArgPair(16, 16);
+
+// Returns a vector of `num_strings` strings. Each std::string represents a
+// floating point number with `num_digits` digits before the decimal point and
+// another `num_digits` digits after.
+std::vector<std::string> MakeFloatStrings(int num_strings, int num_digits) {
+  // For convenience, use a random number generator to generate the test data.
+  // We don't actually need random properties, so use a fixed seed.
+  std::minstd_rand0 rng(1);
+  std::uniform_int_distribution<int> random_digit('0', '9');
+
+  std::vector<std::string> float_strings(num_strings);
+  for (std::string& s : float_strings) {
+    s.reserve(2 * num_digits + 1);
+    for (int i = 0; i < num_digits; ++i) {
+      s.push_back(static_cast<char>(random_digit(rng)));
+    }
+    s.push_back('.');
+    for (int i = 0; i < num_digits; ++i) {
+      s.push_back(static_cast<char>(random_digit(rng)));
+    }
+  }
+  return float_strings;
+}
+
+template <typename StringType>
+StringType GetStringAs(const std::string& s) {
+  return static_cast<StringType>(s);
+}
+template <>
+const char* GetStringAs<const char*>(const std::string& s) {
+  return s.c_str();
+}
+
+template <typename StringType>
+std::vector<StringType> GetStringsAs(const std::vector<std::string>& strings) {
+  std::vector<StringType> result;
+  result.reserve(strings.size());
+  for (const std::string& s : strings) {
+    result.push_back(GetStringAs<StringType>(s));
+  }
+  return result;
+}
+
+template <typename T>
+void BM_SimpleAtof(benchmark::State& state) {
+  const int num_strings = state.range(0);
+  const int num_digits = state.range(1);
+  std::vector<std::string> backing_strings =
+      MakeFloatStrings(num_strings, num_digits);
+  std::vector<T> inputs = GetStringsAs<T>(backing_strings);
+  float value;
+  for (auto _ : state) {
+    for (const T& input : inputs) {
+      benchmark::DoNotOptimize(absl::SimpleAtof(input, &value));
+    }
+  }
+}
+BENCHMARK_TEMPLATE(BM_SimpleAtof, absl::string_view)
+    ->ArgPair(10, 1)
+    ->ArgPair(10, 2)
+    ->ArgPair(10, 4)
+    ->ArgPair(10, 8);
+BENCHMARK_TEMPLATE(BM_SimpleAtof, const char*)
+    ->ArgPair(10, 1)
+    ->ArgPair(10, 2)
+    ->ArgPair(10, 4)
+    ->ArgPair(10, 8);
+BENCHMARK_TEMPLATE(BM_SimpleAtof, std::string)
+    ->ArgPair(10, 1)
+    ->ArgPair(10, 2)
+    ->ArgPair(10, 4)
+    ->ArgPair(10, 8);
+
+template <typename T>
+void BM_SimpleAtod(benchmark::State& state) {
+  const int num_strings = state.range(0);
+  const int num_digits = state.range(1);
+  std::vector<std::string> backing_strings =
+      MakeFloatStrings(num_strings, num_digits);
+  std::vector<T> inputs = GetStringsAs<T>(backing_strings);
+  double value;
+  for (auto _ : state) {
+    for (const T& input : inputs) {
+      benchmark::DoNotOptimize(absl::SimpleAtod(input, &value));
+    }
+  }
+}
+BENCHMARK_TEMPLATE(BM_SimpleAtod, absl::string_view)
+    ->ArgPair(10, 1)
+    ->ArgPair(10, 2)
+    ->ArgPair(10, 4)
+    ->ArgPair(10, 8);
+BENCHMARK_TEMPLATE(BM_SimpleAtod, const char*)
+    ->ArgPair(10, 1)
+    ->ArgPair(10, 2)
+    ->ArgPair(10, 4)
+    ->ArgPair(10, 8);
+BENCHMARK_TEMPLATE(BM_SimpleAtod, std::string)
+    ->ArgPair(10, 1)
+    ->ArgPair(10, 2)
+    ->ArgPair(10, 4)
+    ->ArgPair(10, 8);
+
+}  // namespace
diff --git a/absl/strings/str_format.h b/absl/strings/str_format.h
index a3fb89c7..70a811b7 100644
--- a/absl/strings/str_format.h
+++ b/absl/strings/str_format.h
@@ -244,8 +244,6 @@ template <typename... Args>
 using FormatSpec =
     typename str_format_internal::FormatSpecDeductionBarrier<Args...>::type;
 
-using absl::str_format_internal::ExtendedParsedFormat;
-
 // ParsedFormat
 //
 // A `ParsedFormat` is a class template representing a preparsed `FormatSpec`,