tor-browser

numbers_test.cc (84403B)

---

// 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.

// This file tests string processing functions related to numeric values.

#include "absl/strings/numbers.h"

#include <sys/types.h>

#include <cfenv>  // NOLINT(build/c++11)
#include <cfloat>
#include <cinttypes>
#include <climits>
#include <cmath>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ios>
#include <limits>
#include <numeric>
#include <random>
#include <set>
#include <string>
#include <type_traits>
#include <vector>

#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/log/log.h"
#include "absl/numeric/int128.h"
#include "absl/random/distributions.h"
#include "absl/random/random.h"
#include "absl/strings/internal/numbers_test_common.h"
#include "absl/strings/internal/ostringstream.h"
#include "absl/strings/internal/pow10_helper.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"

namespace {

using absl::SimpleAtoi;
using absl::SimpleHexAtoi;
using absl::numbers_internal::kSixDigitsToBufferSize;
using absl::numbers_internal::safe_strto16_base;
using absl::numbers_internal::safe_strto32_base;
using absl::numbers_internal::safe_strto64_base;
using absl::numbers_internal::safe_strto8_base;
using absl::numbers_internal::safe_strtou16_base;
using absl::numbers_internal::safe_strtou32_base;
using absl::numbers_internal::safe_strtou64_base;
using absl::numbers_internal::safe_strtou8_base;
using absl::numbers_internal::SixDigitsToBuffer;
using absl::strings_internal::Itoa;
using absl::strings_internal::strtouint32_test_cases;
using absl::strings_internal::strtouint64_test_cases;
using testing::Eq;
using testing::MatchesRegex;
using testing::Pointee;

// Number of floats to test with.
// 5,000,000 is a reasonable default for a test that only takes a few seconds.
// 1,000,000,000+ triggers checking for all possible mantissa values for
// double-precision tests. 2,000,000,000+ triggers checking for every possible
// single-precision float.
const int kFloatNumCases = 5000000;

// This is a slow, brute-force routine to compute the exact base-10
// representation of a double-precision floating-point number.  It
// is useful for debugging only.
std::string PerfectDtoa(double d) {
 if (d == 0) return "0";
 if (d < 0) return "-" + PerfectDtoa(-d);

 // Basic theory: decompose d into mantissa and exp, where
 // d = mantissa * 2^exp, and exp is as close to zero as possible.
 int64_t mantissa, exp = 0;
 while (d >= 1ULL << 63) ++exp, d *= 0.5;
 while ((mantissa = d) != d) --exp, d *= 2.0;

 // Then convert mantissa to ASCII, and either double it (if
 // exp > 0) or halve it (if exp < 0) repeatedly.  "halve it"
 // in this case means multiplying it by five and dividing by 10.
 constexpr int maxlen = 1100;  // worst case is actually 1030 or so.
 char buf[maxlen + 5];
 for (int64_t num = mantissa, pos = maxlen; --pos >= 0;) {
   buf[pos] = '0' + (num % 10);
   num /= 10;
 }
 char* begin = &buf[0];
 char* end = buf + maxlen;
 for (int i = 0; i != exp; i += (exp > 0) ? 1 : -1) {
   int carry = 0;
   for (char* p = end; --p != begin;) {
     int dig = *p - '0';
     dig = dig * (exp > 0 ? 2 : 5) + carry;
     carry = dig / 10;
     dig %= 10;
     *p = '0' + dig;
   }
 }
 if (exp < 0) {
   // "dividing by 10" above means we have to add the decimal point.
   memmove(end + 1 + exp, end + exp, 1 - exp);
   end[exp] = '.';
   ++end;
 }
 while (*begin == '0' && begin[1] != '.') ++begin;
 return {begin, end};
}

TEST(ToString, PerfectDtoa) {
 EXPECT_THAT(PerfectDtoa(1), Eq("1"));
 EXPECT_THAT(PerfectDtoa(0.1),
             Eq("0.1000000000000000055511151231257827021181583404541015625"));
 EXPECT_THAT(PerfectDtoa(1e24), Eq("999999999999999983222784"));
 EXPECT_THAT(PerfectDtoa(5e-324), MatchesRegex("0.0000.*625"));
 for (int i = 0; i < 100; ++i) {
   for (double multiplier :
        {1e-300, 1e-200, 1e-100, 0.1, 1.0, 10.0, 1e100, 1e300}) {
     double d = multiplier * i;
     std::string s = PerfectDtoa(d);
     EXPECT_DOUBLE_EQ(d, strtod(s.c_str(), nullptr));
   }
 }
}

template <typename integer>
struct MyInteger {
 integer i;
 explicit constexpr MyInteger(integer i) : i(i) {}
 constexpr operator integer() const { return i; }

 constexpr MyInteger operator+(MyInteger other) const { return i + other.i; }
 constexpr MyInteger operator-(MyInteger other) const { return i - other.i; }
 constexpr MyInteger operator*(MyInteger other) const { return i * other.i; }
 constexpr MyInteger operator/(MyInteger other) const { return i / other.i; }

 constexpr bool operator<(MyInteger other) const { return i < other.i; }
 constexpr bool operator<=(MyInteger other) const { return i <= other.i; }
 constexpr bool operator==(MyInteger other) const { return i == other.i; }
 constexpr bool operator>=(MyInteger other) const { return i >= other.i; }
 constexpr bool operator>(MyInteger other) const { return i > other.i; }
 constexpr bool operator!=(MyInteger other) const { return i != other.i; }

 integer as_integer() const { return i; }
};

typedef MyInteger<int64_t> MyInt64;
typedef MyInteger<uint64_t> MyUInt64;

void CheckInt32(int32_t x) {
 char buffer[absl::numbers_internal::kFastToBufferSize];
 char* actual = absl::numbers_internal::FastIntToBuffer(x, buffer);
 std::string expected = std::to_string(x);
 EXPECT_EQ(expected, std::string(buffer, actual)) << " Input " << x;

 char* generic_actual = absl::numbers_internal::FastIntToBuffer(x, buffer);
 EXPECT_EQ(expected, std::string(buffer, generic_actual)) << " Input " << x;
}

void CheckInt64(int64_t x) {
 char buffer[absl::numbers_internal::kFastToBufferSize + 3];
 buffer[0] = '*';
 buffer[23] = '*';
 buffer[24] = '*';
 char* actual = absl::numbers_internal::FastIntToBuffer(x, &buffer[1]);
 std::string expected = std::to_string(x);
 EXPECT_EQ(expected, std::string(&buffer[1], actual)) << " Input " << x;
 EXPECT_EQ(buffer[0], '*');
 EXPECT_EQ(buffer[23], '*');
 EXPECT_EQ(buffer[24], '*');

 char* my_actual =
     absl::numbers_internal::FastIntToBuffer(MyInt64(x), &buffer[1]);
 EXPECT_EQ(expected, std::string(&buffer[1], my_actual)) << " Input " << x;
}

void CheckUInt32(uint32_t x) {
 char buffer[absl::numbers_internal::kFastToBufferSize];
 char* actual = absl::numbers_internal::FastIntToBuffer(x, buffer);
 std::string expected = std::to_string(x);
 EXPECT_EQ(expected, std::string(buffer, actual)) << " Input " << x;

 char* generic_actual = absl::numbers_internal::FastIntToBuffer(x, buffer);
 EXPECT_EQ(expected, std::string(buffer, generic_actual)) << " Input " << x;
}

void CheckUInt64(uint64_t x) {
 char buffer[absl::numbers_internal::kFastToBufferSize + 1];
 char* actual = absl::numbers_internal::FastIntToBuffer(x, &buffer[1]);
 std::string expected = std::to_string(x);
 EXPECT_EQ(expected, std::string(&buffer[1], actual)) << " Input " << x;

 char* generic_actual = absl::numbers_internal::FastIntToBuffer(x, &buffer[1]);
 EXPECT_EQ(expected, std::string(&buffer[1], generic_actual))
     << " Input " << x;

 char* my_actual =
     absl::numbers_internal::FastIntToBuffer(MyUInt64(x), &buffer[1]);
 EXPECT_EQ(expected, std::string(&buffer[1], my_actual)) << " Input " << x;
}

void CheckHex64(uint64_t v) {
 char expected[16 + 1];
 std::string actual = absl::StrCat(absl::Hex(v, absl::kZeroPad16));
 snprintf(expected, sizeof(expected), "%016" PRIx64, static_cast<uint64_t>(v));
 EXPECT_EQ(expected, actual) << " Input " << v;
 actual = absl::StrCat(absl::Hex(v, absl::kSpacePad16));
 snprintf(expected, sizeof(expected), "%16" PRIx64, static_cast<uint64_t>(v));
 EXPECT_EQ(expected, actual) << " Input " << v;
}

TEST(Numbers, TestFastPrints) {
 for (int i = -100; i <= 100; i++) {
   CheckInt32(i);
   CheckInt64(i);
 }
 for (int i = 0; i <= 100; i++) {
   CheckUInt32(i);
   CheckUInt64(i);
 }
 // Test min int to make sure that works
 CheckInt32(INT_MIN);
 CheckInt32(INT_MAX);
 CheckInt64(LONG_MIN);
 CheckInt64(uint64_t{1000000000});
 CheckInt64(uint64_t{9999999999});
 CheckInt64(uint64_t{100000000000000});
 CheckInt64(uint64_t{999999999999999});
 CheckInt64(uint64_t{1000000000000000000});
 CheckInt64(uint64_t{1199999999999999999});
 CheckInt64(int64_t{-700000000000000000});
 CheckInt64(LONG_MAX);
 CheckUInt32(std::numeric_limits<uint32_t>::max());
 CheckUInt64(uint64_t{1000000000});
 CheckUInt64(uint64_t{9999999999});
 CheckUInt64(uint64_t{100000000000000});
 CheckUInt64(uint64_t{999999999999999});
 CheckUInt64(uint64_t{1000000000000000000});
 CheckUInt64(uint64_t{1199999999999999999});
 CheckUInt64(std::numeric_limits<uint64_t>::max());

 for (int i = 0; i < 10000; i++) {
   CheckHex64(i);
 }
 CheckHex64(uint64_t{0x123456789abcdef0});
}

template <typename int_type, typename in_val_type>
void VerifySimpleAtoiGood(in_val_type in_value, int_type exp_value) {
 std::string s = absl::StrCat(in_value);
 int_type x = static_cast<int_type>(~exp_value);
 EXPECT_TRUE(SimpleAtoi(s, &x))
     << "in_value=" << in_value << " s=" << s << " x=" << x;
 EXPECT_EQ(exp_value, x);
 x = static_cast<int_type>(~exp_value);
 EXPECT_TRUE(SimpleAtoi(s.c_str(), &x));
 EXPECT_EQ(exp_value, x);
}

template <typename int_type, typename in_val_type>
void VerifySimpleAtoiBad(in_val_type in_value) {
 std::string s = absl::StrCat(in_value);
 int_type x;
 EXPECT_FALSE(SimpleAtoi(s, &x));
 EXPECT_FALSE(SimpleAtoi(s.c_str(), &x));
}

TEST(NumbersTest, Atoi) {
 // SimpleAtoi(absl::string_view, int8_t)
 VerifySimpleAtoiGood<int8_t>(0, 0);
 VerifySimpleAtoiGood<int8_t>(42, 42);
 VerifySimpleAtoiGood<int8_t>(-42, -42);

 VerifySimpleAtoiGood<int8_t>(std::numeric_limits<int8_t>::min(),
                              std::numeric_limits<int8_t>::min());
 VerifySimpleAtoiGood<int8_t>(std::numeric_limits<int8_t>::max(),
                              std::numeric_limits<int8_t>::max());

 VerifySimpleAtoiBad<int8_t>(std::numeric_limits<uint8_t>::max());
 VerifySimpleAtoiBad<int8_t>(std::numeric_limits<int16_t>::min());
 VerifySimpleAtoiBad<int8_t>(std::numeric_limits<int16_t>::max());

 // SimpleAtoi(absl::string_view, uint8_t)
 VerifySimpleAtoiGood<uint8_t>(0, 0);
 VerifySimpleAtoiGood<uint8_t>(42, 42);
 VerifySimpleAtoiBad<uint8_t>(-42);

 VerifySimpleAtoiBad<uint8_t>(std::numeric_limits<int8_t>::min());
 VerifySimpleAtoiGood<uint8_t>(std::numeric_limits<int8_t>::max(),
                               std::numeric_limits<int8_t>::max());
 VerifySimpleAtoiGood<uint8_t>(std::numeric_limits<uint8_t>::max(),
                               std::numeric_limits<uint8_t>::max());

 VerifySimpleAtoiBad<uint8_t>(std::numeric_limits<int16_t>::min());
 VerifySimpleAtoiBad<uint8_t>(std::numeric_limits<int16_t>::max());
 VerifySimpleAtoiBad<uint8_t>(std::numeric_limits<uint16_t>::max());

 // SimpleAtoi(absl::string_view, uint16_t)
 VerifySimpleAtoiGood<int16_t>(0, 0);
 VerifySimpleAtoiGood<int16_t>(42, 42);
 VerifySimpleAtoiGood<int16_t>(-42, -42);

 VerifySimpleAtoiGood<int16_t>(std::numeric_limits<int16_t>::min(),
                               std::numeric_limits<int16_t>::min());
 VerifySimpleAtoiGood<int16_t>(std::numeric_limits<int16_t>::max(),
                               std::numeric_limits<int16_t>::max());

 VerifySimpleAtoiBad<int16_t>(std::numeric_limits<uint16_t>::max());
 VerifySimpleAtoiBad<int16_t>(std::numeric_limits<int32_t>::min());
 VerifySimpleAtoiBad<int16_t>(std::numeric_limits<int32_t>::max());

 // SimpleAtoi(absl::string_view, uint16_t)
 VerifySimpleAtoiGood<uint16_t>(0, 0);
 VerifySimpleAtoiGood<uint16_t>(42, 42);
 VerifySimpleAtoiBad<uint16_t>(-42);

 VerifySimpleAtoiBad<uint16_t>(std::numeric_limits<int16_t>::min());
 VerifySimpleAtoiGood<uint16_t>(std::numeric_limits<int16_t>::max(),
                                std::numeric_limits<int16_t>::max());
 VerifySimpleAtoiGood<uint16_t>(std::numeric_limits<uint16_t>::max(),
                                std::numeric_limits<uint16_t>::max());

 VerifySimpleAtoiBad<uint16_t>(std::numeric_limits<int16_t>::min());
 VerifySimpleAtoiBad<uint16_t>(std::numeric_limits<int32_t>::max());
 VerifySimpleAtoiBad<uint16_t>(std::numeric_limits<uint32_t>::max());

 // SimpleAtoi(absl::string_view, int32_t)
 VerifySimpleAtoiGood<int32_t>(0, 0);
 VerifySimpleAtoiGood<int32_t>(42, 42);
 VerifySimpleAtoiGood<int32_t>(-42, -42);

 VerifySimpleAtoiGood<int32_t>(std::numeric_limits<int32_t>::min(),
                               std::numeric_limits<int32_t>::min());
 VerifySimpleAtoiGood<int32_t>(std::numeric_limits<int32_t>::max(),
                               std::numeric_limits<int32_t>::max());

 // SimpleAtoi(absl::string_view, uint32_t)
 VerifySimpleAtoiGood<uint32_t>(0, 0);
 VerifySimpleAtoiGood<uint32_t>(42, 42);
 VerifySimpleAtoiBad<uint32_t>(-42);

 VerifySimpleAtoiBad<uint32_t>(std::numeric_limits<int32_t>::min());
 VerifySimpleAtoiGood<uint32_t>(std::numeric_limits<int32_t>::max(),
                                std::numeric_limits<int32_t>::max());
 VerifySimpleAtoiGood<uint32_t>(std::numeric_limits<uint32_t>::max(),
                                std::numeric_limits<uint32_t>::max());
 VerifySimpleAtoiBad<uint32_t>(std::numeric_limits<int64_t>::min());
 VerifySimpleAtoiBad<uint32_t>(std::numeric_limits<int64_t>::max());
 VerifySimpleAtoiBad<uint32_t>(std::numeric_limits<uint64_t>::max());

 // SimpleAtoi(absl::string_view, int64_t)
 VerifySimpleAtoiGood<int64_t>(0, 0);
 VerifySimpleAtoiGood<int64_t>(42, 42);
 VerifySimpleAtoiGood<int64_t>(-42, -42);

 VerifySimpleAtoiGood<int64_t>(std::numeric_limits<int32_t>::min(),
                               std::numeric_limits<int32_t>::min());
 VerifySimpleAtoiGood<int64_t>(std::numeric_limits<int32_t>::max(),
                               std::numeric_limits<int32_t>::max());
 VerifySimpleAtoiGood<int64_t>(std::numeric_limits<uint32_t>::max(),
                               std::numeric_limits<uint32_t>::max());
 VerifySimpleAtoiGood<int64_t>(std::numeric_limits<int64_t>::min(),
                               std::numeric_limits<int64_t>::min());
 VerifySimpleAtoiGood<int64_t>(std::numeric_limits<int64_t>::max(),
                               std::numeric_limits<int64_t>::max());
 VerifySimpleAtoiBad<int64_t>(std::numeric_limits<uint64_t>::max());

 // SimpleAtoi(absl::string_view, uint64_t)
 VerifySimpleAtoiGood<uint64_t>(0, 0);
 VerifySimpleAtoiGood<uint64_t>(42, 42);
 VerifySimpleAtoiBad<uint64_t>(-42);

 VerifySimpleAtoiBad<uint64_t>(std::numeric_limits<int32_t>::min());
 VerifySimpleAtoiGood<uint64_t>(std::numeric_limits<int32_t>::max(),
                                std::numeric_limits<int32_t>::max());
 VerifySimpleAtoiGood<uint64_t>(std::numeric_limits<uint32_t>::max(),
                                std::numeric_limits<uint32_t>::max());
 VerifySimpleAtoiBad<uint64_t>(std::numeric_limits<int64_t>::min());
 VerifySimpleAtoiGood<uint64_t>(std::numeric_limits<int64_t>::max(),
                                std::numeric_limits<int64_t>::max());
 VerifySimpleAtoiGood<uint64_t>(std::numeric_limits<uint64_t>::max(),
                                std::numeric_limits<uint64_t>::max());

 // SimpleAtoi(absl::string_view, absl::uint128)
 VerifySimpleAtoiGood<absl::uint128>(0, 0);
 VerifySimpleAtoiGood<absl::uint128>(42, 42);
 VerifySimpleAtoiBad<absl::uint128>(-42);

 VerifySimpleAtoiBad<absl::uint128>(std::numeric_limits<int32_t>::min());
 VerifySimpleAtoiGood<absl::uint128>(std::numeric_limits<int32_t>::max(),
                                     std::numeric_limits<int32_t>::max());
 VerifySimpleAtoiGood<absl::uint128>(std::numeric_limits<uint32_t>::max(),
                                     std::numeric_limits<uint32_t>::max());
 VerifySimpleAtoiBad<absl::uint128>(std::numeric_limits<int64_t>::min());
 VerifySimpleAtoiGood<absl::uint128>(std::numeric_limits<int64_t>::max(),
                                     std::numeric_limits<int64_t>::max());
 VerifySimpleAtoiGood<absl::uint128>(std::numeric_limits<uint64_t>::max(),
                                     std::numeric_limits<uint64_t>::max());
 VerifySimpleAtoiGood<absl::uint128>(
     std::numeric_limits<absl::uint128>::max(),
     std::numeric_limits<absl::uint128>::max());

 // SimpleAtoi(absl::string_view, absl::int128)
 VerifySimpleAtoiGood<absl::int128>(0, 0);
 VerifySimpleAtoiGood<absl::int128>(42, 42);
 VerifySimpleAtoiGood<absl::int128>(-42, -42);

 VerifySimpleAtoiGood<absl::int128>(std::numeric_limits<int32_t>::min(),
                                     std::numeric_limits<int32_t>::min());
 VerifySimpleAtoiGood<absl::int128>(std::numeric_limits<int32_t>::max(),
                                     std::numeric_limits<int32_t>::max());
 VerifySimpleAtoiGood<absl::int128>(std::numeric_limits<uint32_t>::max(),
                                     std::numeric_limits<uint32_t>::max());
 VerifySimpleAtoiGood<absl::int128>(std::numeric_limits<int64_t>::min(),
                                     std::numeric_limits<int64_t>::min());
 VerifySimpleAtoiGood<absl::int128>(std::numeric_limits<int64_t>::max(),
                                     std::numeric_limits<int64_t>::max());
 VerifySimpleAtoiGood<absl::int128>(std::numeric_limits<uint64_t>::max(),
                                     std::numeric_limits<uint64_t>::max());
 VerifySimpleAtoiGood<absl::int128>(
     std::numeric_limits<absl::int128>::min(),
     std::numeric_limits<absl::int128>::min());
 VerifySimpleAtoiGood<absl::int128>(
     std::numeric_limits<absl::int128>::max(),
     std::numeric_limits<absl::int128>::max());
 VerifySimpleAtoiBad<absl::int128>(std::numeric_limits<absl::uint128>::max());

 // Some other types
 VerifySimpleAtoiGood<short>(-42, -42);  // NOLINT: runtime-int
 VerifySimpleAtoiGood<int>(-42, -42);
 VerifySimpleAtoiGood<int32_t>(-42, -42);
 VerifySimpleAtoiGood<uint32_t>(42, 42);
 VerifySimpleAtoiGood<unsigned int>(42, 42);
 VerifySimpleAtoiGood<int64_t>(-42, -42);
 VerifySimpleAtoiGood<long>(-42, -42);  // NOLINT: runtime-int
 VerifySimpleAtoiGood<uint64_t>(42, 42);
 VerifySimpleAtoiGood<size_t>(42, 42);
 VerifySimpleAtoiGood<std::string::size_type>(42, 42);
}

TEST(NumbersTest, Atod) {
 // DBL_TRUE_MIN and FLT_TRUE_MIN were not mandated in <cfloat> before C++17.
#if !defined(DBL_TRUE_MIN)
 static constexpr double DBL_TRUE_MIN =
     4.940656458412465441765687928682213723650598026143247644255856825e-324;
#endif
#if !defined(FLT_TRUE_MIN)
 static constexpr float FLT_TRUE_MIN =
     1.401298464324817070923729583289916131280261941876515771757068284e-45f;
#endif

 double d;
 float f;

 // NaN can be spelled in multiple ways.
 EXPECT_TRUE(absl::SimpleAtod("NaN", &d));
 EXPECT_TRUE(std::isnan(d));
 EXPECT_TRUE(absl::SimpleAtod("nAN", &d));
 EXPECT_TRUE(std::isnan(d));
 EXPECT_TRUE(absl::SimpleAtod("-nan", &d));
 EXPECT_TRUE(std::isnan(d));

 // Likewise for Infinity.
 EXPECT_TRUE(absl::SimpleAtod("inf", &d));
 EXPECT_TRUE(std::isinf(d) && (d > 0));
 EXPECT_TRUE(absl::SimpleAtod("+Infinity", &d));
 EXPECT_TRUE(std::isinf(d) && (d > 0));
 EXPECT_TRUE(absl::SimpleAtod("-INF", &d));
 EXPECT_TRUE(std::isinf(d) && (d < 0));

 // Parse DBL_MAX. Parsing something more than twice as big should also
 // produce infinity.
 EXPECT_TRUE(absl::SimpleAtod("1.7976931348623157e+308", &d));
 EXPECT_EQ(d, 1.7976931348623157e+308);
 EXPECT_TRUE(absl::SimpleAtod("5e308", &d));
 EXPECT_TRUE(std::isinf(d) && (d > 0));
 // Ditto, but for FLT_MAX.
 EXPECT_TRUE(absl::SimpleAtof("3.4028234663852886e+38", &f));
 EXPECT_EQ(f, 3.4028234663852886e+38f);
 EXPECT_TRUE(absl::SimpleAtof("7e38", &f));
 EXPECT_TRUE(std::isinf(f) && (f > 0));

 // Parse the largest N such that parsing 1eN produces a finite value and the
 // smallest M = N + 1 such that parsing 1eM produces infinity.
 //
 // The 309 exponent (and 39) confirms the "definition of
 // kEiselLemireMaxExclExp10" comment in charconv.cc.
 EXPECT_TRUE(absl::SimpleAtod("1e308", &d));
 EXPECT_EQ(d, 1e308);
 EXPECT_FALSE(std::isinf(d));
 EXPECT_TRUE(absl::SimpleAtod("1e309", &d));
 EXPECT_TRUE(std::isinf(d));
 // Ditto, but for Atof instead of Atod.
 EXPECT_TRUE(absl::SimpleAtof("1e38", &f));
 EXPECT_EQ(f, 1e38f);
 EXPECT_FALSE(std::isinf(f));
 EXPECT_TRUE(absl::SimpleAtof("1e39", &f));
 EXPECT_TRUE(std::isinf(f));

 // Parse the largest N such that parsing 9.999999999999999999eN, with 19
 // nines, produces a finite value.
 //
 // 9999999999999999999, with 19 nines but no decimal point, is the largest
 // "repeated nines" integer that fits in a uint64_t.
 EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e307", &d));
 EXPECT_EQ(d, 9.999999999999999999e307);
 EXPECT_FALSE(std::isinf(d));
 EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e308", &d));
 EXPECT_TRUE(std::isinf(d));
 // Ditto, but for Atof instead of Atod.
 EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e37", &f));
 EXPECT_EQ(f, 9.999999999999999999e37f);
 EXPECT_FALSE(std::isinf(f));
 EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e38", &f));
 EXPECT_TRUE(std::isinf(f));

 // Parse DBL_MIN (normal), DBL_TRUE_MIN (subnormal) and (DBL_TRUE_MIN / 10)
 // (effectively zero).
 EXPECT_TRUE(absl::SimpleAtod("2.2250738585072014e-308", &d));
 EXPECT_EQ(d, 2.2250738585072014e-308);
 EXPECT_TRUE(absl::SimpleAtod("4.9406564584124654e-324", &d));
 EXPECT_EQ(d, 4.9406564584124654e-324);
 EXPECT_TRUE(absl::SimpleAtod("4.9406564584124654e-325", &d));
 EXPECT_EQ(d, 0);
 // Ditto, but for FLT_MIN, FLT_TRUE_MIN and (FLT_TRUE_MIN / 10).
 EXPECT_TRUE(absl::SimpleAtof("1.1754943508222875e-38", &f));
 EXPECT_EQ(f, 1.1754943508222875e-38f);
 EXPECT_TRUE(absl::SimpleAtof("1.4012984643248171e-45", &f));
 EXPECT_EQ(f, 1.4012984643248171e-45f);
 EXPECT_TRUE(absl::SimpleAtof("1.4012984643248171e-46", &f));
 EXPECT_EQ(f, 0);

 // Parse the largest N (the most negative -N) such that parsing 1e-N produces
 // a normal or subnormal (but still positive) or zero value.
 EXPECT_TRUE(absl::SimpleAtod("1e-307", &d));
 EXPECT_EQ(d, 1e-307);
 EXPECT_GE(d, DBL_MIN);
 EXPECT_LT(d, DBL_MIN * 10);
 EXPECT_TRUE(absl::SimpleAtod("1e-323", &d));
 EXPECT_EQ(d, 1e-323);
 EXPECT_GE(d, DBL_TRUE_MIN);
 EXPECT_LT(d, DBL_TRUE_MIN * 10);
 EXPECT_TRUE(absl::SimpleAtod("1e-324", &d));
 EXPECT_EQ(d, 0);
 // Ditto, but for Atof instead of Atod.
 EXPECT_TRUE(absl::SimpleAtof("1e-37", &f));
 EXPECT_EQ(f, 1e-37f);
 EXPECT_GE(f, FLT_MIN);
 EXPECT_LT(f, FLT_MIN * 10);
 EXPECT_TRUE(absl::SimpleAtof("1e-45", &f));
 EXPECT_EQ(f, 1e-45f);
 EXPECT_GE(f, FLT_TRUE_MIN);
 EXPECT_LT(f, FLT_TRUE_MIN * 10);
 EXPECT_TRUE(absl::SimpleAtof("1e-46", &f));
 EXPECT_EQ(f, 0);

 // Parse the largest N (the most negative -N) such that parsing
 // 9.999999999999999999e-N, with 19 nines, produces a normal or subnormal
 // (but still positive) or zero value.
 //
 // 9999999999999999999, with 19 nines but no decimal point, is the largest
 // "repeated nines" integer that fits in a uint64_t.
 //
 // The -324/-325 exponents (and -46/-47) confirms the "definition of
 // kEiselLemireMinInclExp10" comment in charconv.cc.
 EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e-308", &d));
 EXPECT_EQ(d, 9.999999999999999999e-308);
 EXPECT_GE(d, DBL_MIN);
 EXPECT_LT(d, DBL_MIN * 10);
 EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e-324", &d));
 EXPECT_EQ(d, 9.999999999999999999e-324);
 EXPECT_GE(d, DBL_TRUE_MIN);
 EXPECT_LT(d, DBL_TRUE_MIN * 10);
 EXPECT_TRUE(absl::SimpleAtod("9.999999999999999999e-325", &d));
 EXPECT_EQ(d, 0);
 // Ditto, but for Atof instead of Atod.
 EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e-38", &f));
 EXPECT_EQ(f, 9.999999999999999999e-38f);
 EXPECT_GE(f, FLT_MIN);
 EXPECT_LT(f, FLT_MIN * 10);
 EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e-46", &f));
 EXPECT_EQ(f, 9.999999999999999999e-46f);
 EXPECT_GE(f, FLT_TRUE_MIN);
 EXPECT_LT(f, FLT_TRUE_MIN * 10);
 EXPECT_TRUE(absl::SimpleAtof("9.999999999999999999e-47", &f));
 EXPECT_EQ(f, 0);

 // Leading and/or trailing whitespace is OK.
 EXPECT_TRUE(absl::SimpleAtod("  \t\r\n  2.718", &d));
 EXPECT_EQ(d, 2.718);
 EXPECT_TRUE(absl::SimpleAtod("  3.141  ", &d));
 EXPECT_EQ(d, 3.141);

 // Leading or trailing not-whitespace is not OK.
 EXPECT_FALSE(absl::SimpleAtod("n 0", &d));
 EXPECT_FALSE(absl::SimpleAtod("0n ", &d));

 // Multiple leading 0s are OK.
 EXPECT_TRUE(absl::SimpleAtod("000123", &d));
 EXPECT_EQ(d, 123);
 EXPECT_TRUE(absl::SimpleAtod("000.456", &d));
 EXPECT_EQ(d, 0.456);

 // An absent leading 0 (for a fraction < 1) is OK.
 EXPECT_TRUE(absl::SimpleAtod(".5", &d));
 EXPECT_EQ(d, 0.5);
 EXPECT_TRUE(absl::SimpleAtod("-.707", &d));
 EXPECT_EQ(d, -0.707);

 // Unary + is OK.
 EXPECT_TRUE(absl::SimpleAtod("+6.0221408e+23", &d));
 EXPECT_EQ(d, 6.0221408e+23);

 // Underscores are not OK.
 EXPECT_FALSE(absl::SimpleAtod("123_456", &d));

 // The decimal separator must be '.' and is never ','.
 EXPECT_TRUE(absl::SimpleAtod("8.9", &d));
 EXPECT_FALSE(absl::SimpleAtod("8,9", &d));

 // These examples are called out in the EiselLemire function's comments.
 EXPECT_TRUE(absl::SimpleAtod("4503599627370497.5", &d));
 EXPECT_EQ(d, 4503599627370497.5);
 EXPECT_TRUE(absl::SimpleAtod("1e+23", &d));
 EXPECT_EQ(d, 1e+23);
 EXPECT_TRUE(absl::SimpleAtod("9223372036854775807", &d));
 EXPECT_EQ(d, 9223372036854775807);
 // Ditto, but for Atof instead of Atod.
 EXPECT_TRUE(absl::SimpleAtof("0.0625", &f));
 EXPECT_EQ(f, 0.0625f);
 EXPECT_TRUE(absl::SimpleAtof("20040229.0", &f));
 EXPECT_EQ(f, 20040229.0f);
 EXPECT_TRUE(absl::SimpleAtof("2147483647.0", &f));
 EXPECT_EQ(f, 2147483647.0f);

 // Some parsing algorithms don't always round correctly (but absl::SimpleAtod
 // should). This test case comes from
 // https://github.com/serde-rs/json/issues/707
 //
 // See also atod_manual_test.cc for running many more test cases.
 EXPECT_TRUE(absl::SimpleAtod("122.416294033786585", &d));
 EXPECT_EQ(d, 122.416294033786585);
 EXPECT_TRUE(absl::SimpleAtof("122.416294033786585", &f));
 EXPECT_EQ(f, 122.416294033786585f);
}

TEST(NumbersTest, Prefixes) {
 double d;
 EXPECT_FALSE(absl::SimpleAtod("++1", &d));
 EXPECT_FALSE(absl::SimpleAtod("+-1", &d));
 EXPECT_FALSE(absl::SimpleAtod("-+1", &d));
 EXPECT_FALSE(absl::SimpleAtod("--1", &d));
 EXPECT_TRUE(absl::SimpleAtod("-1", &d));
 EXPECT_EQ(d, -1.);
 EXPECT_TRUE(absl::SimpleAtod("+1", &d));
 EXPECT_EQ(d, +1.);

 float f;
 EXPECT_FALSE(absl::SimpleAtof("++1", &f));
 EXPECT_FALSE(absl::SimpleAtof("+-1", &f));
 EXPECT_FALSE(absl::SimpleAtof("-+1", &f));
 EXPECT_FALSE(absl::SimpleAtof("--1", &f));
 EXPECT_TRUE(absl::SimpleAtof("-1", &f));
 EXPECT_EQ(f, -1.f);
 EXPECT_TRUE(absl::SimpleAtof("+1", &f));
 EXPECT_EQ(f, +1.f);
}

TEST(NumbersTest, Atoenum) {
 enum E01 {
   E01_zero = 0,
   E01_one = 1,
 };

 VerifySimpleAtoiGood<E01>(E01_zero, E01_zero);
 VerifySimpleAtoiGood<E01>(E01_one, E01_one);

 enum E_101 {
   E_101_minusone = -1,
   E_101_zero = 0,
   E_101_one = 1,
 };

 VerifySimpleAtoiGood<E_101>(E_101_minusone, E_101_minusone);
 VerifySimpleAtoiGood<E_101>(E_101_zero, E_101_zero);
 VerifySimpleAtoiGood<E_101>(E_101_one, E_101_one);

 enum E_bigint {
   E_bigint_zero = 0,
   E_bigint_one = 1,
   E_bigint_max31 = static_cast<int32_t>(0x7FFFFFFF),
 };

 VerifySimpleAtoiGood<E_bigint>(E_bigint_zero, E_bigint_zero);
 VerifySimpleAtoiGood<E_bigint>(E_bigint_one, E_bigint_one);
 VerifySimpleAtoiGood<E_bigint>(E_bigint_max31, E_bigint_max31);

 enum E_fullint {
   E_fullint_zero = 0,
   E_fullint_one = 1,
   E_fullint_max31 = static_cast<int32_t>(0x7FFFFFFF),
   E_fullint_min32 = INT32_MIN,
 };

 VerifySimpleAtoiGood<E_fullint>(E_fullint_zero, E_fullint_zero);
 VerifySimpleAtoiGood<E_fullint>(E_fullint_one, E_fullint_one);
 VerifySimpleAtoiGood<E_fullint>(E_fullint_max31, E_fullint_max31);
 VerifySimpleAtoiGood<E_fullint>(E_fullint_min32, E_fullint_min32);

 enum E_biguint {
   E_biguint_zero = 0,
   E_biguint_one = 1,
   E_biguint_max31 = static_cast<uint32_t>(0x7FFFFFFF),
   E_biguint_max32 = static_cast<uint32_t>(0xFFFFFFFF),
 };

 VerifySimpleAtoiGood<E_biguint>(E_biguint_zero, E_biguint_zero);
 VerifySimpleAtoiGood<E_biguint>(E_biguint_one, E_biguint_one);
 VerifySimpleAtoiGood<E_biguint>(E_biguint_max31, E_biguint_max31);
 VerifySimpleAtoiGood<E_biguint>(E_biguint_max32, E_biguint_max32);
}

template <typename int_type, typename in_val_type>
void VerifySimpleHexAtoiGood(in_val_type in_value, int_type exp_value) {
 std::string s;
 absl::strings_internal::OStringStream strm(&s);
 if (in_value >= 0) {
   if constexpr (std::is_arithmetic<in_val_type>::value) {
     absl::StrAppend(&s, absl::Hex(in_value));
   } else {
     // absl::Hex doesn't work with absl::(u)int128.
     strm << std::hex << in_value;
   }
 } else {
   // Inefficient for small integers, but works with all integral types.
   strm << "-" << std::hex << -absl::uint128(in_value);
 }
 int_type x = static_cast<int_type>(~exp_value);
 EXPECT_TRUE(SimpleHexAtoi(s, &x))
     << "in_value=" << std::hex << in_value << " s=" << s << " x=" << x;
 EXPECT_EQ(exp_value, x);
 x = static_cast<int_type>(~exp_value);
 EXPECT_TRUE(SimpleHexAtoi(
     s.c_str(), &x));  // NOLINT: readability-redundant-string-conversions
 EXPECT_EQ(exp_value, x);
}

template <typename int_type, typename in_val_type>
void VerifySimpleHexAtoiBad(in_val_type in_value) {
 std::string s;
 absl::strings_internal::OStringStream strm(&s);
 if (in_value >= 0) {
   if constexpr (std::is_arithmetic<in_val_type>::value) {
     absl::StrAppend(&s, absl::Hex(in_value));
   } else {
     // absl::Hex doesn't work with absl::(u)int128.
     strm << std::hex << in_value;
   }
 } else {
   // Inefficient for small integers, but works with all integral types.
   strm << "-" << std::hex << -absl::uint128(in_value);
 }
 int_type x;
 EXPECT_FALSE(SimpleHexAtoi(s, &x));
 EXPECT_FALSE(SimpleHexAtoi(
     s.c_str(), &x));  // NOLINT: readability-redundant-string-conversions
}

TEST(NumbersTest, HexAtoi) {
 // SimpleHexAtoi(absl::string_view, int8_t)
 VerifySimpleHexAtoiGood<int8_t>(0, 0);
 VerifySimpleHexAtoiGood<int8_t>(0x42, 0x42);
 VerifySimpleHexAtoiGood<int8_t>(-0x42, -0x42);

 VerifySimpleHexAtoiGood<int8_t>(std::numeric_limits<int8_t>::min(),
                                 std::numeric_limits<int8_t>::min());
 VerifySimpleHexAtoiGood<int8_t>(std::numeric_limits<int8_t>::max(),
                                 std::numeric_limits<int8_t>::max());

 // SimpleHexAtoi(absl::string_view, uint8_t)
 VerifySimpleHexAtoiGood<uint8_t>(0, 0);
 VerifySimpleHexAtoiGood<uint8_t>(0x42, 0x42);
 VerifySimpleHexAtoiBad<uint8_t>(-0x42);

 VerifySimpleHexAtoiBad<uint8_t>(std::numeric_limits<int8_t>::min());
 VerifySimpleHexAtoiGood<uint8_t>(std::numeric_limits<int8_t>::max(),
                                  std::numeric_limits<int8_t>::max());
 VerifySimpleHexAtoiGood<uint8_t>(std::numeric_limits<uint8_t>::max(),
                                  std::numeric_limits<uint8_t>::max());
 VerifySimpleHexAtoiBad<uint8_t>(std::numeric_limits<int16_t>::min());
 VerifySimpleHexAtoiBad<uint8_t>(std::numeric_limits<int16_t>::max());
 VerifySimpleHexAtoiBad<uint8_t>(std::numeric_limits<uint16_t>::max());

 // SimpleHexAtoi(absl::string_view, int16_t)
 VerifySimpleHexAtoiGood<int16_t>(0, 0);
 VerifySimpleHexAtoiGood<int16_t>(0x42, 0x42);
 VerifySimpleHexAtoiGood<int16_t>(-0x42, -0x42);

 VerifySimpleHexAtoiGood<int16_t>(std::numeric_limits<int16_t>::min(),
                                  std::numeric_limits<int16_t>::min());
 VerifySimpleHexAtoiGood<int16_t>(std::numeric_limits<int16_t>::max(),
                                  std::numeric_limits<int16_t>::max());

 // SimpleHexAtoi(absl::string_view, uint16_t)
 VerifySimpleHexAtoiGood<uint16_t>(0, 0);
 VerifySimpleHexAtoiGood<uint16_t>(0x42, 0x42);
 VerifySimpleHexAtoiBad<uint16_t>(-0x42);

 VerifySimpleHexAtoiBad<uint16_t>(std::numeric_limits<int16_t>::min());
 VerifySimpleHexAtoiGood<uint16_t>(std::numeric_limits<int16_t>::max(),
                                   std::numeric_limits<int16_t>::max());
 VerifySimpleHexAtoiGood<uint16_t>(std::numeric_limits<uint16_t>::max(),
                                   std::numeric_limits<uint16_t>::max());
 VerifySimpleHexAtoiBad<uint16_t>(std::numeric_limits<int32_t>::min());
 VerifySimpleHexAtoiBad<uint16_t>(std::numeric_limits<int32_t>::max());
 VerifySimpleHexAtoiBad<uint16_t>(std::numeric_limits<uint32_t>::max());

 // SimpleHexAtoi(absl::string_view, int32_t)
 VerifySimpleHexAtoiGood<int32_t>(0, 0);
 VerifySimpleHexAtoiGood<int32_t>(0x42, 0x42);
 VerifySimpleHexAtoiGood<int32_t>(-0x42, -0x42);

 VerifySimpleHexAtoiGood<int32_t>(std::numeric_limits<int32_t>::min(),
                                  std::numeric_limits<int32_t>::min());
 VerifySimpleHexAtoiGood<int32_t>(std::numeric_limits<int32_t>::max(),
                                  std::numeric_limits<int32_t>::max());

 // SimpleHexAtoi(absl::string_view, uint32_t)
 VerifySimpleHexAtoiGood<uint32_t>(0, 0);
 VerifySimpleHexAtoiGood<uint32_t>(0x42, 0x42);
 VerifySimpleHexAtoiBad<uint32_t>(-0x42);

 VerifySimpleHexAtoiBad<uint32_t>(std::numeric_limits<int32_t>::min());
 VerifySimpleHexAtoiGood<uint32_t>(std::numeric_limits<int32_t>::max(),
                                   std::numeric_limits<int32_t>::max());
 VerifySimpleHexAtoiGood<uint32_t>(std::numeric_limits<uint32_t>::max(),
                                   std::numeric_limits<uint32_t>::max());
 VerifySimpleHexAtoiBad<uint32_t>(std::numeric_limits<int64_t>::min());
 VerifySimpleHexAtoiBad<uint32_t>(std::numeric_limits<int64_t>::max());
 VerifySimpleHexAtoiBad<uint32_t>(std::numeric_limits<uint64_t>::max());

 // SimpleHexAtoi(absl::string_view, int64_t)
 VerifySimpleHexAtoiGood<int64_t>(0, 0);
 VerifySimpleHexAtoiGood<int64_t>(0x42, 0x42);
 VerifySimpleHexAtoiGood<int64_t>(-0x42, -0x42);

 VerifySimpleHexAtoiGood<int64_t>(std::numeric_limits<int32_t>::min(),
                                  std::numeric_limits<int32_t>::min());
 VerifySimpleHexAtoiGood<int64_t>(std::numeric_limits<int32_t>::max(),
                                  std::numeric_limits<int32_t>::max());
 VerifySimpleHexAtoiGood<int64_t>(std::numeric_limits<uint32_t>::max(),
                                  std::numeric_limits<uint32_t>::max());
 VerifySimpleHexAtoiGood<int64_t>(std::numeric_limits<int64_t>::min(),
                                  std::numeric_limits<int64_t>::min());
 VerifySimpleHexAtoiGood<int64_t>(std::numeric_limits<int64_t>::max(),
                                  std::numeric_limits<int64_t>::max());
 VerifySimpleHexAtoiBad<int64_t>(std::numeric_limits<uint64_t>::max());

 // SimpleHexAtoi(absl::string_view, uint64_t)
 VerifySimpleHexAtoiGood<uint64_t>(0, 0);
 VerifySimpleHexAtoiGood<uint64_t>(0x42, 0x42);
 VerifySimpleHexAtoiBad<uint64_t>(-0x42);

 VerifySimpleHexAtoiBad<uint64_t>(std::numeric_limits<int32_t>::min());
 VerifySimpleHexAtoiGood<uint64_t>(std::numeric_limits<int32_t>::max(),
                                   std::numeric_limits<int32_t>::max());
 VerifySimpleHexAtoiGood<uint64_t>(std::numeric_limits<uint32_t>::max(),
                                   std::numeric_limits<uint32_t>::max());
 VerifySimpleHexAtoiBad<uint64_t>(std::numeric_limits<int64_t>::min());
 VerifySimpleHexAtoiGood<uint64_t>(std::numeric_limits<int64_t>::max(),
                                   std::numeric_limits<int64_t>::max());
 VerifySimpleHexAtoiGood<uint64_t>(std::numeric_limits<uint64_t>::max(),
                                   std::numeric_limits<uint64_t>::max());

 // SimpleHexAtoi(absl::string_view, absl::uint128)
 VerifySimpleHexAtoiGood<absl::uint128>(0, 0);
 VerifySimpleHexAtoiGood<absl::uint128>(0x42, 0x42);
 VerifySimpleHexAtoiBad<absl::uint128>(-0x42);

 VerifySimpleHexAtoiBad<absl::uint128>(std::numeric_limits<int32_t>::min());
 VerifySimpleHexAtoiGood<absl::uint128>(std::numeric_limits<int32_t>::max(),
                                        std::numeric_limits<int32_t>::max());
 VerifySimpleHexAtoiGood<absl::uint128>(std::numeric_limits<uint32_t>::max(),
                                        std::numeric_limits<uint32_t>::max());
 VerifySimpleHexAtoiBad<absl::uint128>(std::numeric_limits<int64_t>::min());
 VerifySimpleHexAtoiGood<absl::uint128>(std::numeric_limits<int64_t>::max(),
                                        std::numeric_limits<int64_t>::max());
 VerifySimpleHexAtoiGood<absl::uint128>(std::numeric_limits<uint64_t>::max(),
                                        std::numeric_limits<uint64_t>::max());
 VerifySimpleHexAtoiGood<absl::uint128>(
     std::numeric_limits<absl::uint128>::max(),
     std::numeric_limits<absl::uint128>::max());

 // Some other types
 VerifySimpleHexAtoiGood<short>(-0x42, -0x42);  // NOLINT: runtime-int
 VerifySimpleHexAtoiGood<int>(-0x42, -0x42);
 VerifySimpleHexAtoiGood<int32_t>(-0x42, -0x42);
 VerifySimpleHexAtoiGood<uint32_t>(0x42, 0x42);
 VerifySimpleHexAtoiGood<unsigned int>(0x42, 0x42);
 VerifySimpleHexAtoiGood<int64_t>(-0x42, -0x42);
 VerifySimpleHexAtoiGood<long>(-0x42, -0x42);  // NOLINT: runtime-int
 VerifySimpleHexAtoiGood<uint64_t>(0x42, 0x42);
 VerifySimpleHexAtoiGood<size_t>(0x42, 0x42);
 VerifySimpleHexAtoiGood<std::string::size_type>(0x42, 0x42);

 // Number prefix
 int32_t value;
 EXPECT_TRUE(safe_strto32_base("0x34234324", &value, 16));
 EXPECT_EQ(0x34234324, value);

 EXPECT_TRUE(safe_strto32_base("0X34234324", &value, 16));
 EXPECT_EQ(0x34234324, value);

 // ASCII whitespace
 EXPECT_TRUE(safe_strto32_base(" \t\n 34234324", &value, 16));
 EXPECT_EQ(0x34234324, value);

 EXPECT_TRUE(safe_strto32_base("34234324 \t\n ", &value, 16));
 EXPECT_EQ(0x34234324, value);
}

TEST(stringtest, safe_strto8_base) {
 int8_t value;
 EXPECT_TRUE(safe_strto8_base("0x34", &value, 16));
 EXPECT_EQ(0x34, value);

 EXPECT_TRUE(safe_strto8_base("0X34", &value, 16));
 EXPECT_EQ(0x34, value);

 EXPECT_TRUE(safe_strto8_base("34", &value, 16));
 EXPECT_EQ(0x34, value);

 EXPECT_TRUE(safe_strto8_base("0", &value, 16));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto8_base(" \t\n -0x34", &value, 16));
 EXPECT_EQ(-0x34, value);

 EXPECT_TRUE(safe_strto8_base(" \t\n -34", &value, 16));
 EXPECT_EQ(-0x34, value);

 EXPECT_TRUE(safe_strto8_base("76", &value, 8));
 EXPECT_EQ(076, value);

 EXPECT_TRUE(safe_strto8_base("-0123", &value, 8));
 EXPECT_EQ(-0123, value);

 EXPECT_FALSE(safe_strto8_base("183", &value, 8));

 // Autodetect base.
 EXPECT_TRUE(safe_strto8_base("0", &value, 0));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto8_base("077", &value, 0));
 EXPECT_EQ(077, value);  // Octal interpretation

 // Leading zero indicates octal, but then followed by invalid digit.
 EXPECT_FALSE(safe_strto8_base("088", &value, 0));

 // Leading 0x indicated hex, but then followed by invalid digit.
 EXPECT_FALSE(safe_strto8_base("0xG", &value, 0));

 // Base-10 version.
 EXPECT_TRUE(safe_strto8_base("124", &value, 10));
 EXPECT_EQ(124, value);

 EXPECT_TRUE(safe_strto8_base("0", &value, 10));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto8_base(" \t\n -124", &value, 10));
 EXPECT_EQ(-124, value);

 EXPECT_TRUE(safe_strto8_base("124 \n\t ", &value, 10));
 EXPECT_EQ(124, value);

 // Invalid ints.
 EXPECT_FALSE(safe_strto8_base("", &value, 10));
 EXPECT_FALSE(safe_strto8_base("  ", &value, 10));
 EXPECT_FALSE(safe_strto8_base("abc", &value, 10));
 EXPECT_FALSE(safe_strto8_base("34a", &value, 10));
 EXPECT_FALSE(safe_strto8_base("34.3", &value, 10));

 // Out of bounds.
 EXPECT_FALSE(safe_strto8_base("128", &value, 10));
 EXPECT_FALSE(safe_strto8_base("-129", &value, 10));

 // String version.
 EXPECT_TRUE(safe_strto8_base(std::string("0x12"), &value, 16));
 EXPECT_EQ(0x12, value);

 // Base-10 string version.
 EXPECT_TRUE(safe_strto8_base("123", &value, 10));
 EXPECT_EQ(123, value);
}

TEST(stringtest, safe_strto16_base) {
 int16_t value;
 EXPECT_TRUE(safe_strto16_base("0x3423", &value, 16));
 EXPECT_EQ(0x3423, value);

 EXPECT_TRUE(safe_strto16_base("0X3423", &value, 16));
 EXPECT_EQ(0x3423, value);

 EXPECT_TRUE(safe_strto16_base("3423", &value, 16));
 EXPECT_EQ(0x3423, value);

 EXPECT_TRUE(safe_strto16_base("0", &value, 16));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto16_base(" \t\n -0x3423", &value, 16));
 EXPECT_EQ(-0x3423, value);

 EXPECT_TRUE(safe_strto16_base(" \t\n -3423", &value, 16));
 EXPECT_EQ(-0x3423, value);

 EXPECT_TRUE(safe_strto16_base("34567", &value, 8));
 EXPECT_EQ(034567, value);

 EXPECT_TRUE(safe_strto16_base("-01234", &value, 8));
 EXPECT_EQ(-01234, value);

 EXPECT_FALSE(safe_strto16_base("1834", &value, 8));

 // Autodetect base.
 EXPECT_TRUE(safe_strto16_base("0", &value, 0));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto16_base("077", &value, 0));
 EXPECT_EQ(077, value);  // Octal interpretation

 // Leading zero indicates octal, but then followed by invalid digit.
 EXPECT_FALSE(safe_strto16_base("088", &value, 0));

 // Leading 0x indicated hex, but then followed by invalid digit.
 EXPECT_FALSE(safe_strto16_base("0xG", &value, 0));

 // Base-10 version.
 EXPECT_TRUE(safe_strto16_base("3423", &value, 10));
 EXPECT_EQ(3423, value);

 EXPECT_TRUE(safe_strto16_base("0", &value, 10));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto16_base(" \t\n -3423", &value, 10));
 EXPECT_EQ(-3423, value);

 EXPECT_TRUE(safe_strto16_base("3423 \n\t ", &value, 10));
 EXPECT_EQ(3423, value);

 // Invalid ints.
 EXPECT_FALSE(safe_strto16_base("", &value, 10));
 EXPECT_FALSE(safe_strto16_base("  ", &value, 10));
 EXPECT_FALSE(safe_strto16_base("abc", &value, 10));
 EXPECT_FALSE(safe_strto16_base("324a", &value, 10));
 EXPECT_FALSE(safe_strto16_base("4234.3", &value, 10));

 // Out of bounds.
 EXPECT_FALSE(safe_strto16_base("32768", &value, 10));
 EXPECT_FALSE(safe_strto16_base("-32769", &value, 10));

 // String version.
 EXPECT_TRUE(safe_strto16_base(std::string("0x1234"), &value, 16));
 EXPECT_EQ(0x1234, value);

 // Base-10 string version.
 EXPECT_TRUE(safe_strto16_base("1234", &value, 10));
 EXPECT_EQ(1234, value);
}

TEST(stringtest, safe_strto32_base) {
 int32_t value;
 EXPECT_TRUE(safe_strto32_base("0x34234324", &value, 16));
 EXPECT_EQ(0x34234324, value);

 EXPECT_TRUE(safe_strto32_base("0X34234324", &value, 16));
 EXPECT_EQ(0x34234324, value);

 EXPECT_TRUE(safe_strto32_base("34234324", &value, 16));
 EXPECT_EQ(0x34234324, value);

 EXPECT_TRUE(safe_strto32_base("0", &value, 16));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto32_base(" \t\n -0x34234324", &value, 16));
 EXPECT_EQ(-0x34234324, value);

 EXPECT_TRUE(safe_strto32_base(" \t\n -34234324", &value, 16));
 EXPECT_EQ(-0x34234324, value);

 EXPECT_TRUE(safe_strto32_base("7654321", &value, 8));
 EXPECT_EQ(07654321, value);

 EXPECT_TRUE(safe_strto32_base("-01234", &value, 8));
 EXPECT_EQ(-01234, value);

 EXPECT_FALSE(safe_strto32_base("1834", &value, 8));

 // Autodetect base.
 EXPECT_TRUE(safe_strto32_base("0", &value, 0));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto32_base("077", &value, 0));
 EXPECT_EQ(077, value);  // Octal interpretation

 // Leading zero indicates octal, but then followed by invalid digit.
 EXPECT_FALSE(safe_strto32_base("088", &value, 0));

 // Leading 0x indicated hex, but then followed by invalid digit.
 EXPECT_FALSE(safe_strto32_base("0xG", &value, 0));

 // Base-10 version.
 EXPECT_TRUE(safe_strto32_base("34234324", &value, 10));
 EXPECT_EQ(34234324, value);

 EXPECT_TRUE(safe_strto32_base("0", &value, 10));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto32_base(" \t\n -34234324", &value, 10));
 EXPECT_EQ(-34234324, value);

 EXPECT_TRUE(safe_strto32_base("34234324 \n\t ", &value, 10));
 EXPECT_EQ(34234324, value);

 // Invalid ints.
 EXPECT_FALSE(safe_strto32_base("", &value, 10));
 EXPECT_FALSE(safe_strto32_base("  ", &value, 10));
 EXPECT_FALSE(safe_strto32_base("abc", &value, 10));
 EXPECT_FALSE(safe_strto32_base("34234324a", &value, 10));
 EXPECT_FALSE(safe_strto32_base("34234.3", &value, 10));

 // Out of bounds.
 EXPECT_FALSE(safe_strto32_base("2147483648", &value, 10));
 EXPECT_FALSE(safe_strto32_base("-2147483649", &value, 10));

 // String version.
 EXPECT_TRUE(safe_strto32_base(std::string("0x1234"), &value, 16));
 EXPECT_EQ(0x1234, value);

 // Base-10 string version.
 EXPECT_TRUE(safe_strto32_base("1234", &value, 10));
 EXPECT_EQ(1234, value);
}

TEST(stringtest, safe_strto64_base) {
 int64_t value;
 EXPECT_TRUE(safe_strto64_base("0x3423432448783446", &value, 16));
 EXPECT_EQ(int64_t{0x3423432448783446}, value);

 EXPECT_TRUE(safe_strto64_base("3423432448783446", &value, 16));
 EXPECT_EQ(int64_t{0x3423432448783446}, value);

 EXPECT_TRUE(safe_strto64_base("0", &value, 16));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto64_base(" \t\n -0x3423432448783446", &value, 16));
 EXPECT_EQ(int64_t{-0x3423432448783446}, value);

 EXPECT_TRUE(safe_strto64_base(" \t\n -3423432448783446", &value, 16));
 EXPECT_EQ(int64_t{-0x3423432448783446}, value);

 EXPECT_TRUE(safe_strto64_base("123456701234567012", &value, 8));
 EXPECT_EQ(int64_t{0123456701234567012}, value);

 EXPECT_TRUE(safe_strto64_base("-017777777777777", &value, 8));
 EXPECT_EQ(int64_t{-017777777777777}, value);

 EXPECT_FALSE(safe_strto64_base("19777777777777", &value, 8));

 // Autodetect base.
 EXPECT_TRUE(safe_strto64_base("0", &value, 0));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto64_base("077", &value, 0));
 EXPECT_EQ(077, value);  // Octal interpretation

 // Leading zero indicates octal, but then followed by invalid digit.
 EXPECT_FALSE(safe_strto64_base("088", &value, 0));

 // Leading 0x indicated hex, but then followed by invalid digit.
 EXPECT_FALSE(safe_strto64_base("0xG", &value, 0));

 // Base-10 version.
 EXPECT_TRUE(safe_strto64_base("34234324487834466", &value, 10));
 EXPECT_EQ(int64_t{34234324487834466}, value);

 EXPECT_TRUE(safe_strto64_base("0", &value, 10));
 EXPECT_EQ(0, value);

 EXPECT_TRUE(safe_strto64_base(" \t\n -34234324487834466", &value, 10));
 EXPECT_EQ(int64_t{-34234324487834466}, value);

 EXPECT_TRUE(safe_strto64_base("34234324487834466 \n\t ", &value, 10));
 EXPECT_EQ(int64_t{34234324487834466}, value);

 // Invalid ints.
 EXPECT_FALSE(safe_strto64_base("", &value, 10));
 EXPECT_FALSE(safe_strto64_base("  ", &value, 10));
 EXPECT_FALSE(safe_strto64_base("abc", &value, 10));
 EXPECT_FALSE(safe_strto64_base("34234324487834466a", &value, 10));
 EXPECT_FALSE(safe_strto64_base("34234487834466.3", &value, 10));

 // Out of bounds.
 EXPECT_FALSE(safe_strto64_base("9223372036854775808", &value, 10));
 EXPECT_FALSE(safe_strto64_base("-9223372036854775809", &value, 10));

 // String version.
 EXPECT_TRUE(safe_strto64_base(std::string("0x1234"), &value, 16));
 EXPECT_EQ(0x1234, value);

 // Base-10 string version.
 EXPECT_TRUE(safe_strto64_base("1234", &value, 10));
 EXPECT_EQ(1234, value);
}

TEST(stringtest, safe_strto8_range) {
 // These tests verify underflow/overflow behaviour.
 int8_t value;
 EXPECT_FALSE(safe_strto8_base("128", &value, 10));
 EXPECT_EQ(std::numeric_limits<int8_t>::max(), value);

 EXPECT_TRUE(safe_strto8_base("-128", &value, 10));
 EXPECT_EQ(std::numeric_limits<int8_t>::min(), value);

 EXPECT_FALSE(safe_strto8_base("-129", &value, 10));
 EXPECT_EQ(std::numeric_limits<int8_t>::min(), value);
}

TEST(stringtest, safe_strto16_range) {
 // These tests verify underflow/overflow behaviour.
 int16_t value;
 EXPECT_FALSE(safe_strto16_base("32768", &value, 10));
 EXPECT_EQ(std::numeric_limits<int16_t>::max(), value);

 EXPECT_TRUE(safe_strto16_base("-32768", &value, 10));
 EXPECT_EQ(std::numeric_limits<int16_t>::min(), value);

 EXPECT_FALSE(safe_strto16_base("-32769", &value, 10));
 EXPECT_EQ(std::numeric_limits<int16_t>::min(), value);
}

TEST(stringtest, safe_strto32_range) {
 // These tests verify underflow/overflow behaviour.
 int32_t value;
 EXPECT_FALSE(safe_strto32_base("2147483648", &value, 10));
 EXPECT_EQ(std::numeric_limits<int32_t>::max(), value);

 EXPECT_TRUE(safe_strto32_base("-2147483648", &value, 10));
 EXPECT_EQ(std::numeric_limits<int32_t>::min(), value);

 EXPECT_FALSE(safe_strto32_base("-2147483649", &value, 10));
 EXPECT_EQ(std::numeric_limits<int32_t>::min(), value);
}

TEST(stringtest, safe_strto64_range) {
 // These tests verify underflow/overflow behaviour.
 int64_t value;
 EXPECT_FALSE(safe_strto64_base("9223372036854775808", &value, 10));
 EXPECT_EQ(std::numeric_limits<int64_t>::max(), value);

 EXPECT_TRUE(safe_strto64_base("-9223372036854775808", &value, 10));
 EXPECT_EQ(std::numeric_limits<int64_t>::min(), value);

 EXPECT_FALSE(safe_strto64_base("-9223372036854775809", &value, 10));
 EXPECT_EQ(std::numeric_limits<int64_t>::min(), value);
}

TEST(stringtest, safe_strto8_leading_substring) {
 // These tests verify this comment in numbers.h:
 // On error, returns false, and sets *value to: [...]
 //   conversion of leading substring if available ("123@@@" -> 123)
 //   0 if no leading substring available
 int8_t value;
 EXPECT_FALSE(safe_strto8_base("069@@@", &value, 10));
 EXPECT_EQ(69, value);

 EXPECT_FALSE(safe_strto8_base("01769@@@", &value, 8));
 EXPECT_EQ(0176, value);

 EXPECT_FALSE(safe_strto8_base("069balloons", &value, 10));
 EXPECT_EQ(69, value);

 EXPECT_FALSE(safe_strto8_base("07bland", &value, 16));
 EXPECT_EQ(0x7b, value);

 EXPECT_FALSE(safe_strto8_base("@@@", &value, 10));
 EXPECT_EQ(0, value);  // there was no leading substring
}

TEST(stringtest, safe_strto16_leading_substring) {
 // These tests verify this comment in numbers.h:
 // On error, returns false, and sets *value to: [...]
 //   conversion of leading substring if available ("123@@@" -> 123)
 //   0 if no leading substring available
 int16_t value;
 EXPECT_FALSE(safe_strto16_base("04069@@@", &value, 10));
 EXPECT_EQ(4069, value);

 EXPECT_FALSE(safe_strto16_base("04069@@@", &value, 8));
 EXPECT_EQ(0406, value);

 EXPECT_FALSE(safe_strto16_base("04069balloons", &value, 10));
 EXPECT_EQ(4069, value);

 EXPECT_FALSE(safe_strto16_base("069balloons", &value, 16));
 EXPECT_EQ(0x69ba, value);

 EXPECT_FALSE(safe_strto16_base("@@@", &value, 10));
 EXPECT_EQ(0, value);  // there was no leading substring
}

TEST(stringtest, safe_strto32_leading_substring) {
 // These tests verify this comment in numbers.h:
 // On error, returns false, and sets *value to: [...]
 //   conversion of leading substring if available ("123@@@" -> 123)
 //   0 if no leading substring available
 int32_t value;
 EXPECT_FALSE(safe_strto32_base("04069@@@", &value, 10));
 EXPECT_EQ(4069, value);

 EXPECT_FALSE(safe_strto32_base("04069@@@", &value, 8));
 EXPECT_EQ(0406, value);

 EXPECT_FALSE(safe_strto32_base("04069balloons", &value, 10));
 EXPECT_EQ(4069, value);

 EXPECT_FALSE(safe_strto32_base("04069balloons", &value, 16));
 EXPECT_EQ(0x4069ba, value);

 EXPECT_FALSE(safe_strto32_base("@@@", &value, 10));
 EXPECT_EQ(0, value);  // there was no leading substring
}

TEST(stringtest, safe_strto64_leading_substring) {
 // These tests verify this comment in numbers.h:
 // On error, returns false, and sets *value to: [...]
 //   conversion of leading substring if available ("123@@@" -> 123)
 //   0 if no leading substring available
 int64_t value;
 EXPECT_FALSE(safe_strto64_base("04069@@@", &value, 10));
 EXPECT_EQ(4069, value);

 EXPECT_FALSE(safe_strto64_base("04069@@@", &value, 8));
 EXPECT_EQ(0406, value);

 EXPECT_FALSE(safe_strto64_base("04069balloons", &value, 10));
 EXPECT_EQ(4069, value);

 EXPECT_FALSE(safe_strto64_base("04069balloons", &value, 16));
 EXPECT_EQ(0x4069ba, value);

 EXPECT_FALSE(safe_strto64_base("@@@", &value, 10));
 EXPECT_EQ(0, value);  // there was no leading substring
}

const size_t kNumRandomTests = 10000;

template <typename IntType>
void test_random_integer_parse_base(bool (*parse_func)(absl::string_view,
                                                      IntType* value,
                                                      int base)) {
 using RandomEngine = std::minstd_rand0;
 std::random_device rd;
 RandomEngine rng(rd());
 std::uniform_int_distribution<IntType> random_int(
     std::numeric_limits<IntType>::min());
 std::uniform_int_distribution<int> random_base(2, 36);
 for (size_t i = 0; i < kNumRandomTests; i++) {
   IntType value = random_int(rng);
   int base = random_base(rng);
   std::string str_value;
   EXPECT_TRUE(Itoa<IntType>(value, base, &str_value));
   IntType parsed_value;

   // Test successful parse
   EXPECT_TRUE(parse_func(str_value, &parsed_value, base));
   EXPECT_EQ(parsed_value, value);

   // Test overflow
   EXPECT_FALSE(
       parse_func(absl::StrCat(std::numeric_limits<IntType>::max(), value),
                  &parsed_value, base));

   // Test underflow
   if (std::numeric_limits<IntType>::min() < 0) {
     EXPECT_FALSE(
         parse_func(absl::StrCat(std::numeric_limits<IntType>::min(), value),
                    &parsed_value, base));
   } else {
     EXPECT_FALSE(parse_func(absl::StrCat("-", value), &parsed_value, base));
   }
 }
}

TEST(stringtest, safe_strto16_random) {
 test_random_integer_parse_base<int16_t>(&safe_strto16_base);
}
TEST(stringtest, safe_strto32_random) {
 test_random_integer_parse_base<int32_t>(&safe_strto32_base);
}
TEST(stringtest, safe_strto64_random) {
 test_random_integer_parse_base<int64_t>(&safe_strto64_base);
}
TEST(stringtest, safe_strtou16_random) {
 test_random_integer_parse_base<uint16_t>(&safe_strtou16_base);
}
TEST(stringtest, safe_strtou32_random) {
 test_random_integer_parse_base<uint32_t>(&safe_strtou32_base);
}
TEST(stringtest, safe_strtou64_random) {
 test_random_integer_parse_base<uint64_t>(&safe_strtou64_base);
}
TEST(stringtest, safe_strtou128_random) {
 // random number generators don't work for uint128 so this code must be custom
 // implemented for uint128, but is generally the same as what's above.
 // test_random_integer_parse_base<absl::uint128>(
 //     &absl::numbers_internal::safe_strtou128_base);
 using RandomEngine = std::minstd_rand0;
 using IntType = absl::uint128;
 constexpr auto parse_func = &absl::numbers_internal::safe_strtou128_base;

 std::random_device rd;
 RandomEngine rng(rd());
 std::uniform_int_distribution<uint64_t> random_uint64(
     std::numeric_limits<uint64_t>::min());
 std::uniform_int_distribution<int> random_base(2, 36);

 for (size_t i = 0; i < kNumRandomTests; i++) {
   IntType value = random_uint64(rng);
   value = (value << 64) + random_uint64(rng);
   int base = random_base(rng);
   std::string str_value;
   EXPECT_TRUE(Itoa<IntType>(value, base, &str_value));
   IntType parsed_value;

   // Test successful parse
   EXPECT_TRUE(parse_func(str_value, &parsed_value, base));
   EXPECT_EQ(parsed_value, value);

   // Test overflow
   EXPECT_FALSE(
       parse_func(absl::StrCat(std::numeric_limits<IntType>::max(), value),
                  &parsed_value, base));

   // Test underflow
   EXPECT_FALSE(parse_func(absl::StrCat("-", value), &parsed_value, base));
 }
}
TEST(stringtest, safe_strto128_random) {
 // random number generators don't work for int128 so this code must be custom
 // implemented for int128, but is generally the same as what's above.
 // test_random_integer_parse_base<absl::int128>(
 //     &absl::numbers_internal::safe_strto128_base);
 using RandomEngine = std::minstd_rand0;
 using IntType = absl::int128;
 constexpr auto parse_func = &absl::numbers_internal::safe_strto128_base;

 std::random_device rd;
 RandomEngine rng(rd());
 std::uniform_int_distribution<int64_t> random_int64(
     std::numeric_limits<int64_t>::min());
 std::uniform_int_distribution<uint64_t> random_uint64(
     std::numeric_limits<uint64_t>::min());
 std::uniform_int_distribution<int> random_base(2, 36);

 for (size_t i = 0; i < kNumRandomTests; ++i) {
   int64_t high = random_int64(rng);
   uint64_t low = random_uint64(rng);
   IntType value = absl::MakeInt128(high, low);

   int base = random_base(rng);
   std::string str_value;
   EXPECT_TRUE(Itoa<IntType>(value, base, &str_value));
   IntType parsed_value;

   // Test successful parse
   EXPECT_TRUE(parse_func(str_value, &parsed_value, base));
   EXPECT_EQ(parsed_value, value);

   // Test overflow
   EXPECT_FALSE(
       parse_func(absl::StrCat(std::numeric_limits<IntType>::max(), value),
                  &parsed_value, base));

   // Test underflow
   EXPECT_FALSE(
       parse_func(absl::StrCat(std::numeric_limits<IntType>::min(), value),
                  &parsed_value, base));
 }
}

TEST(stringtest, safe_strtou8_exhaustive) {
 // Testing the entire space for uint8_t since it is small.
 using IntType = uint8_t;
 constexpr auto parse_func = &absl::numbers_internal::safe_strtou8_base;

 for (int i = std::numeric_limits<IntType>::min();
      i <= std::numeric_limits<IntType>::max(); i++) {
   IntType value = static_cast<IntType>(i);
   for (int base = 2; base <= 36; base++) {
     std::string str_value;
     EXPECT_TRUE(Itoa<IntType>(value, base, &str_value));
     IntType parsed_value;

     // Test successful parse
     EXPECT_TRUE(parse_func(str_value, &parsed_value, base));
     EXPECT_EQ(parsed_value, value);

     // Test overflow
     EXPECT_FALSE(
         parse_func(absl::StrCat(std::numeric_limits<IntType>::max(), value),
                    &parsed_value, base));
     // Test underflow
     EXPECT_FALSE(parse_func(absl::StrCat("-", value), &parsed_value, base));
   }
 }
}

TEST(stringtest, safe_strto8_exhaustive) {
 // Testing the entire space for int8_t since it is small.
 using IntType = int8_t;
 constexpr auto parse_func = &absl::numbers_internal::safe_strto8_base;

 for (int i = std::numeric_limits<IntType>::min();
      i <= std::numeric_limits<IntType>::max(); i++) {
   IntType value = static_cast<IntType>(i);
   for (int base = 2; base <= 36; base++) {
     std::string str_value;
     EXPECT_TRUE(Itoa<IntType>(value, base, &str_value));
     IntType parsed_value;

     // Test successful parse
     EXPECT_TRUE(parse_func(str_value, &parsed_value, base));
     EXPECT_EQ(parsed_value, value);

     // Test overflow
     EXPECT_FALSE(
         parse_func(absl::StrCat(std::numeric_limits<IntType>::max(), value),
                    &parsed_value, base));
     // Test underflow
     EXPECT_FALSE(
         parse_func(absl::StrCat(std::numeric_limits<IntType>::min(), value),
                    &parsed_value, base));
   }
 }
}

TEST(stringtest, safe_strtou32_base) {
 for (int i = 0; strtouint32_test_cases()[i].str != nullptr; ++i) {
   const auto& e = strtouint32_test_cases()[i];
   uint32_t value;
   EXPECT_EQ(e.expect_ok, safe_strtou32_base(e.str, &value, e.base))
       << "str=\"" << e.str << "\" base=" << e.base;
   if (e.expect_ok) {
     EXPECT_EQ(e.expected, value) << "i=" << i << " str=\"" << e.str
                                  << "\" base=" << e.base;
   }
 }
}

TEST(stringtest, safe_strtou32_base_length_delimited) {
 for (int i = 0; strtouint32_test_cases()[i].str != nullptr; ++i) {
   const auto& e = strtouint32_test_cases()[i];
   std::string tmp(e.str);
   tmp.append("12");  // Adds garbage at the end.

   uint32_t value;
   EXPECT_EQ(e.expect_ok,
             safe_strtou32_base(absl::string_view(tmp.data(), strlen(e.str)),
                                &value, e.base))
       << "str=\"" << e.str << "\" base=" << e.base;
   if (e.expect_ok) {
     EXPECT_EQ(e.expected, value) << "i=" << i << " str=" << e.str
                                  << " base=" << e.base;
   }
 }
}

TEST(stringtest, safe_strtou64_base) {
 for (int i = 0; strtouint64_test_cases()[i].str != nullptr; ++i) {
   const auto& e = strtouint64_test_cases()[i];
   uint64_t value;
   EXPECT_EQ(e.expect_ok, safe_strtou64_base(e.str, &value, e.base))
       << "str=\"" << e.str << "\" base=" << e.base;
   if (e.expect_ok) {
     EXPECT_EQ(e.expected, value) << "str=" << e.str << " base=" << e.base;
   }
 }
}

TEST(stringtest, safe_strtou64_base_length_delimited) {
 for (int i = 0; strtouint64_test_cases()[i].str != nullptr; ++i) {
   const auto& e = strtouint64_test_cases()[i];
   std::string tmp(e.str);
   tmp.append("12");  // Adds garbage at the end.

   uint64_t value;
   EXPECT_EQ(e.expect_ok,
             safe_strtou64_base(absl::string_view(tmp.data(), strlen(e.str)),
                                &value, e.base))
       << "str=\"" << e.str << "\" base=" << e.base;
   if (e.expect_ok) {
     EXPECT_EQ(e.expected, value) << "str=\"" << e.str << "\" base=" << e.base;
   }
 }
}

// feenableexcept() and fedisableexcept() are extensions supported by some libc
// implementations.
#if defined(__GLIBC__) || defined(__BIONIC__)
#define ABSL_HAVE_FEENABLEEXCEPT 1
#define ABSL_HAVE_FEDISABLEEXCEPT 1
#endif

class SimpleDtoaTest : public testing::Test {
protected:
 void SetUp() override {
   // Store the current floating point env & clear away any pending exceptions.
   feholdexcept(&fp_env_);
#ifdef ABSL_HAVE_FEENABLEEXCEPT
   // Turn on floating point exceptions.
   feenableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW);
#endif
 }

 void TearDown() override {
   // Restore the floating point environment to the original state.
   // In theory fedisableexcept is unnecessary; fesetenv will also do it.
   // In practice, our toolchains have subtle bugs.
#ifdef ABSL_HAVE_FEDISABLEEXCEPT
   fedisableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW);
#endif
   fesetenv(&fp_env_);
 }

 std::string ToNineDigits(double value) {
   char buffer[16];  // more than enough for %.9g
   snprintf(buffer, sizeof(buffer), "%.9g", value);
   return buffer;
 }

 fenv_t fp_env_;
};

// Run the given runnable functor for "cases" test cases, chosen over the
// available range of float.  pi and e and 1/e are seeded, and then all
// available integer powers of 2 and 10 are multiplied against them.  In
// addition to trying all those values, we try the next higher and next lower
// float, and then we add additional test cases evenly distributed between them.
// Each test case is passed to runnable as both a positive and negative value.
template <typename R>
void ExhaustiveFloat(uint32_t cases, R&& runnable) {
 runnable(0.0f);
 runnable(-0.0f);
 if (cases >= 2e9) {  // more than 2 billion?  Might as well run them all.
   for (float f = 0; f < std::numeric_limits<float>::max(); ) {
     f = nextafterf(f, std::numeric_limits<float>::max());
     runnable(-f);
     runnable(f);
   }
   return;
 }
 std::set<float> floats = {3.4028234e38f};
 for (float f : {1.0, 3.14159265, 2.718281828, 1 / 2.718281828}) {
   for (float testf = f; testf != 0; testf *= 0.1f) floats.insert(testf);
   for (float testf = f; testf != 0; testf *= 0.5f) floats.insert(testf);
   for (float testf = f; testf < 3e38f / 2; testf *= 2.0f)
     floats.insert(testf);
   for (float testf = f; testf < 3e38f / 10; testf *= 10) floats.insert(testf);
 }

 float last = *floats.begin();

 runnable(last);
 runnable(-last);
 int iters_per_float = cases / floats.size();
 if (iters_per_float == 0) iters_per_float = 1;
 for (float f : floats) {
   if (f == last) continue;
   float testf = std::nextafter(last, std::numeric_limits<float>::max());
   runnable(testf);
   runnable(-testf);
   last = testf;
   if (f == last) continue;
   double step = (double{f} - last) / iters_per_float;
   for (double d = last + step; d < f; d += step) {
     testf = d;
     if (testf != last) {
       runnable(testf);
       runnable(-testf);
       last = testf;
     }
   }
   testf = std::nextafter(f, 0.0f);
   if (testf > last) {
     runnable(testf);
     runnable(-testf);
     last = testf;
   }
   if (f != last) {
     runnable(f);
     runnable(-f);
     last = f;
   }
 }
}

TEST_F(SimpleDtoaTest, ExhaustiveDoubleToSixDigits) {
 uint64_t test_count = 0;
 std::vector<double> mismatches;
 auto checker = [&](double d) {
   if (d != d) return;  // rule out NaNs
   ++test_count;
   char sixdigitsbuf[kSixDigitsToBufferSize] = {0};
   SixDigitsToBuffer(d, sixdigitsbuf);
   char snprintfbuf[kSixDigitsToBufferSize] = {0};
   snprintf(snprintfbuf, kSixDigitsToBufferSize, "%g", d);
   if (strcmp(sixdigitsbuf, snprintfbuf) != 0) {
     mismatches.push_back(d);
     if (mismatches.size() < 10) {
       LOG(ERROR) << "Six-digit failure with double.  d=" << d
                  << " sixdigits=" << sixdigitsbuf
                  << " printf(%g)=" << snprintfbuf;
     }
   }
 };
 // Some quick sanity checks...
 checker(5e-324);
 checker(1e-308);
 checker(1.0);
 checker(1.000005);
 checker(1.7976931348623157e308);
 checker(0.00390625);
#ifndef _MSC_VER
 // on MSVC, snprintf() rounds it to 0.00195313. SixDigitsToBuffer() rounds it
 // to 0.00195312 (round half to even).
 checker(0.001953125);
#endif
 checker(0.005859375);
 // Some cases where the rounding is very very close
 checker(1.089095e-15);
 checker(3.274195e-55);
 checker(6.534355e-146);
 checker(2.920845e+234);

 if (mismatches.empty()) {
   test_count = 0;
   ExhaustiveFloat(kFloatNumCases, checker);

   test_count = 0;
   std::vector<int> digit_testcases{
       100000, 100001, 100002, 100005, 100010, 100020, 100050, 100100,  // misc
       195312, 195313,  // 1.953125 is a case where we round down, just barely.
       200000, 500000, 800000,  // misc mid-range cases
       585937, 585938,  // 5.859375 is a case where we round up, just barely.
       900000, 990000, 999000, 999900, 999990, 999996, 999997, 999998, 999999};
   if (kFloatNumCases >= 1e9) {
     // If at least 1 billion test cases were requested, user wants an
     // exhaustive test. So let's test all mantissas, too.
     constexpr int min_mantissa = 100000, max_mantissa = 999999;
     digit_testcases.resize(max_mantissa - min_mantissa + 1);
     std::iota(digit_testcases.begin(), digit_testcases.end(), min_mantissa);
   }

   for (int exponent = -324; exponent <= 308; ++exponent) {
     double powten = absl::strings_internal::Pow10(exponent);
     if (powten == 0) powten = 5e-324;
     if (kFloatNumCases >= 1e9) {
       // The exhaustive test takes a very long time, so log progress.
       char buf[kSixDigitsToBufferSize];
       LOG(INFO) << "Exp " << exponent << " powten=" << powten << "(" << powten
                 << ") ("
                 << absl::string_view(buf, SixDigitsToBuffer(powten, buf))
                 << ")";
     }
     for (int digits : digit_testcases) {
       if (exponent == 308 && digits >= 179769) break;  // don't overflow!
       double digiform = (digits + 0.5) * 0.00001;
       double testval = digiform * powten;
       double pretestval = nextafter(testval, 0);
       double posttestval = nextafter(testval, 1.7976931348623157e308);
       checker(testval);
       checker(pretestval);
       checker(posttestval);
     }
   }
 } else {
   EXPECT_EQ(mismatches.size(), 0);
   for (size_t i = 0; i < mismatches.size(); ++i) {
     if (i > 100) i = mismatches.size() - 1;
     double d = mismatches[i];
     char sixdigitsbuf[kSixDigitsToBufferSize] = {0};
     SixDigitsToBuffer(d, sixdigitsbuf);
     char snprintfbuf[kSixDigitsToBufferSize] = {0};
     snprintf(snprintfbuf, kSixDigitsToBufferSize, "%g", d);
     double before = nextafter(d, 0.0);
     double after = nextafter(d, 1.7976931348623157e308);
     char b1[32], b2[kSixDigitsToBufferSize];
     LOG(ERROR) << "Mismatch #" << i << "  d=" << d << " (" << ToNineDigits(d)
                << ") sixdigits='" << sixdigitsbuf << "' snprintf='"
                << snprintfbuf << "' Before.=" << PerfectDtoa(before) << " "
                << (SixDigitsToBuffer(before, b2), b2) << " vs snprintf="
                << (snprintf(b1, sizeof(b1), "%g", before), b1)
                << " Perfect=" << PerfectDtoa(d) << " "
                << (SixDigitsToBuffer(d, b2), b2)
                << " vs snprintf=" << (snprintf(b1, sizeof(b1), "%g", d), b1)
                << " After.=." << PerfectDtoa(after) << " "
                << (SixDigitsToBuffer(after, b2), b2) << " vs snprintf="
                << (snprintf(b1, sizeof(b1), "%g", after), b1);
   }
 }
}

TEST(StrToInt8, Partial) {
 struct Int8TestLine {
   std::string input;
   bool status;
   int8_t value;
 };
 const int8_t int8_min = std::numeric_limits<int8_t>::min();
 const int8_t int8_max = std::numeric_limits<int8_t>::max();
 Int8TestLine int8_test_line[] = {
     {"", false, 0},
     {" ", false, 0},
     {"-", false, 0},
     {"123@@@", false, 123},
     {absl::StrCat(int8_min, int8_max), false, int8_min},
     {absl::StrCat(int8_max, int8_max), false, int8_max},
 };

 for (const Int8TestLine& test_line : int8_test_line) {
   int8_t value = -2;
   bool status = safe_strto8_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = -2;
   status = safe_strto8_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = -2;
   status = safe_strto8_base(absl::string_view(test_line.input), &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
 }
}

TEST(StrToUint8, Partial) {
 struct Uint8TestLine {
   std::string input;
   bool status;
   uint8_t value;
 };
 const uint8_t uint8_max = std::numeric_limits<uint8_t>::max();
 Uint8TestLine uint8_test_line[] = {
     {"", false, 0},
     {" ", false, 0},
     {"-", false, 0},
     {"123@@@", false, 123},
     {absl::StrCat(uint8_max, uint8_max), false, uint8_max},
 };

 for (const Uint8TestLine& test_line : uint8_test_line) {
   uint8_t value = 2;
   bool status = safe_strtou8_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = 2;
   status = safe_strtou8_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = 2;
   status = safe_strtou8_base(absl::string_view(test_line.input), &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
 }
}

TEST(StrToInt16, Partial) {
 struct Int16TestLine {
   std::string input;
   bool status;
   int16_t value;
 };
 const int16_t int16_min = std::numeric_limits<int16_t>::min();
 const int16_t int16_max = std::numeric_limits<int16_t>::max();
 Int16TestLine int16_test_line[] = {
     {"", false, 0},
     {" ", false, 0},
     {"-", false, 0},
     {"123@@@", false, 123},
     {absl::StrCat(int16_min, int16_max), false, int16_min},
     {absl::StrCat(int16_max, int16_max), false, int16_max},
 };

 for (const Int16TestLine& test_line : int16_test_line) {
   int16_t value = -2;
   bool status = safe_strto16_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = -2;
   status = safe_strto16_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = -2;
   status = safe_strto16_base(absl::string_view(test_line.input), &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
 }
}

TEST(StrToUint16, Partial) {
 struct Uint16TestLine {
   std::string input;
   bool status;
   uint16_t value;
 };
 const uint16_t uint16_max = std::numeric_limits<uint16_t>::max();
 Uint16TestLine uint16_test_line[] = {
     {"", false, 0},
     {" ", false, 0},
     {"-", false, 0},
     {"123@@@", false, 123},
     {absl::StrCat(uint16_max, uint16_max), false, uint16_max},
 };

 for (const Uint16TestLine& test_line : uint16_test_line) {
   uint16_t value = 2;
   bool status = safe_strtou16_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = 2;
   status = safe_strtou16_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = 2;
   status = safe_strtou16_base(absl::string_view(test_line.input), &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
 }
}

TEST(StrToInt32, Partial) {
 struct Int32TestLine {
   std::string input;
   bool status;
   int32_t value;
 };
 const int32_t int32_min = std::numeric_limits<int32_t>::min();
 const int32_t int32_max = std::numeric_limits<int32_t>::max();
 Int32TestLine int32_test_line[] = {
     {"", false, 0},
     {" ", false, 0},
     {"-", false, 0},
     {"123@@@", false, 123},
     {absl::StrCat(int32_min, int32_max), false, int32_min},
     {absl::StrCat(int32_max, int32_max), false, int32_max},
 };

 for (const Int32TestLine& test_line : int32_test_line) {
   int32_t value = -2;
   bool status = safe_strto32_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = -2;
   status = safe_strto32_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = -2;
   status = safe_strto32_base(absl::string_view(test_line.input), &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
 }
}

TEST(StrToUint32, Partial) {
 struct Uint32TestLine {
   std::string input;
   bool status;
   uint32_t value;
 };
 const uint32_t uint32_max = std::numeric_limits<uint32_t>::max();
 Uint32TestLine uint32_test_line[] = {
     {"", false, 0},
     {" ", false, 0},
     {"-", false, 0},
     {"123@@@", false, 123},
     {absl::StrCat(uint32_max, uint32_max), false, uint32_max},
 };

 for (const Uint32TestLine& test_line : uint32_test_line) {
   uint32_t value = 2;
   bool status = safe_strtou32_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = 2;
   status = safe_strtou32_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = 2;
   status = safe_strtou32_base(absl::string_view(test_line.input), &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
 }
}

TEST(StrToInt64, Partial) {
 struct Int64TestLine {
   std::string input;
   bool status;
   int64_t value;
 };
 const int64_t int64_min = std::numeric_limits<int64_t>::min();
 const int64_t int64_max = std::numeric_limits<int64_t>::max();
 Int64TestLine int64_test_line[] = {
     {"", false, 0},
     {" ", false, 0},
     {"-", false, 0},
     {"123@@@", false, 123},
     {absl::StrCat(int64_min, int64_max), false, int64_min},
     {absl::StrCat(int64_max, int64_max), false, int64_max},
 };

 for (const Int64TestLine& test_line : int64_test_line) {
   int64_t value = -2;
   bool status = safe_strto64_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = -2;
   status = safe_strto64_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = -2;
   status = safe_strto64_base(absl::string_view(test_line.input), &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
 }
}

TEST(StrToUint64, Partial) {
 struct Uint64TestLine {
   std::string input;
   bool status;
   uint64_t value;
 };
 const uint64_t uint64_max = std::numeric_limits<uint64_t>::max();
 Uint64TestLine uint64_test_line[] = {
     {"", false, 0},
     {" ", false, 0},
     {"-", false, 0},
     {"123@@@", false, 123},
     {absl::StrCat(uint64_max, uint64_max), false, uint64_max},
 };

 for (const Uint64TestLine& test_line : uint64_test_line) {
   uint64_t value = 2;
   bool status = safe_strtou64_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = 2;
   status = safe_strtou64_base(test_line.input, &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
   value = 2;
   status = safe_strtou64_base(absl::string_view(test_line.input), &value, 10);
   EXPECT_EQ(test_line.status, status) << test_line.input;
   EXPECT_EQ(test_line.value, value) << test_line.input;
 }
}

TEST(StrToInt32Base, PrefixOnly) {
 struct Int32TestLine {
   std::string input;
   bool status;
   int32_t value;
 };
 Int32TestLine int32_test_line[] = {
   { "", false, 0 },
   { "-", false, 0 },
   { "-0", true, 0 },
   { "0", true, 0 },
   { "0x", false, 0 },
   { "-0x", false, 0 },
 };
 const int base_array[] = { 0, 2, 8, 10, 16 };

 for (const Int32TestLine& line : int32_test_line) {
   for (const int base : base_array) {
     int32_t value = 2;
     bool status = safe_strto32_base(line.input.c_str(), &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
     value = 2;
     status = safe_strto32_base(line.input, &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
     value = 2;
     status = safe_strto32_base(absl::string_view(line.input), &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
   }
 }
}

TEST(StrToUint32Base, PrefixOnly) {
 struct Uint32TestLine {
   std::string input;
   bool status;
   uint32_t value;
 };
 Uint32TestLine uint32_test_line[] = {
   { "", false, 0 },
   { "0", true, 0 },
   { "0x", false, 0 },
 };
 const int base_array[] = { 0, 2, 8, 10, 16 };

 for (const Uint32TestLine& line : uint32_test_line) {
   for (const int base : base_array) {
     uint32_t value = 2;
     bool status = safe_strtou32_base(line.input.c_str(), &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
     value = 2;
     status = safe_strtou32_base(line.input, &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
     value = 2;
     status = safe_strtou32_base(absl::string_view(line.input), &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
   }
 }
}

TEST(StrToInt64Base, PrefixOnly) {
 struct Int64TestLine {
   std::string input;
   bool status;
   int64_t value;
 };
 Int64TestLine int64_test_line[] = {
   { "", false, 0 },
   { "-", false, 0 },
   { "-0", true, 0 },
   { "0", true, 0 },
   { "0x", false, 0 },
   { "-0x", false, 0 },
 };
 const int base_array[] = { 0, 2, 8, 10, 16 };

 for (const Int64TestLine& line : int64_test_line) {
   for (const int base : base_array) {
     int64_t value = 2;
     bool status = safe_strto64_base(line.input.c_str(), &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
     value = 2;
     status = safe_strto64_base(line.input, &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
     value = 2;
     status = safe_strto64_base(absl::string_view(line.input), &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
   }
 }
}

TEST(StrToUint64Base, PrefixOnly) {
 struct Uint64TestLine {
   std::string input;
   bool status;
   uint64_t value;
 };
 Uint64TestLine uint64_test_line[] = {
   { "", false, 0 },
   { "0", true, 0 },
   { "0x", false, 0 },
 };
 const int base_array[] = { 0, 2, 8, 10, 16 };

 for (const Uint64TestLine& line : uint64_test_line) {
   for (const int base : base_array) {
     uint64_t value = 2;
     bool status = safe_strtou64_base(line.input.c_str(), &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
     value = 2;
     status = safe_strtou64_base(line.input, &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
     value = 2;
     status = safe_strtou64_base(absl::string_view(line.input), &value, base);
     EXPECT_EQ(line.status, status) << line.input << " " << base;
     EXPECT_EQ(line.value, value) << line.input << " " << base;
   }
 }
}

void TestFastHexToBufferZeroPad16(uint64_t v) {
 char buf[16];
 auto digits = absl::numbers_internal::FastHexToBufferZeroPad16(v, buf);
 absl::string_view res(buf, 16);
 char buf2[17];
 snprintf(buf2, sizeof(buf2), "%016" PRIx64, v);
 EXPECT_EQ(res, buf2) << v;
 size_t expected_digits = snprintf(buf2, sizeof(buf2), "%" PRIx64, v);
 EXPECT_EQ(digits, expected_digits) << v;
}

TEST(FastHexToBufferZeroPad16, Smoke) {
 TestFastHexToBufferZeroPad16(std::numeric_limits<uint64_t>::min());
 TestFastHexToBufferZeroPad16(std::numeric_limits<uint64_t>::max());
 TestFastHexToBufferZeroPad16(std::numeric_limits<int64_t>::min());
 TestFastHexToBufferZeroPad16(std::numeric_limits<int64_t>::max());
 absl::BitGen rng;
 for (int i = 0; i < 100000; ++i) {
   TestFastHexToBufferZeroPad16(
       absl::LogUniform(rng, std::numeric_limits<uint64_t>::min(),
                        std::numeric_limits<uint64_t>::max()));
 }
}

template <typename Int>
void ExpectWritesNull() {
 {
   char buf[absl::numbers_internal::kFastToBufferSize];
   Int x = std::numeric_limits<Int>::min();
   EXPECT_THAT(absl::numbers_internal::FastIntToBuffer(x, buf), Pointee('\0'));
 }
 {
   char buf[absl::numbers_internal::kFastToBufferSize];
   Int x = std::numeric_limits<Int>::max();
   EXPECT_THAT(absl::numbers_internal::FastIntToBuffer(x, buf), Pointee('\0'));
 }
}

TEST(FastIntToBuffer, WritesNull) {
 ExpectWritesNull<int8_t>();
 ExpectWritesNull<uint8_t>();
 ExpectWritesNull<int16_t>();
 ExpectWritesNull<uint16_t>();
 ExpectWritesNull<int32_t>();
 ExpectWritesNull<uint32_t>();
 ExpectWritesNull<int64_t>();
 ExpectWritesNull<uint32_t>();
}

}  // namespace