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Diffstat (limited to 'absl/random/internal/iostream_state_saver_test.cc')
| -rw-r--r-- | absl/random/internal/iostream_state_saver_test.cc | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/absl/random/internal/iostream_state_saver_test.cc b/absl/random/internal/iostream_state_saver_test.cc new file mode 100644 index 000000000000..2ecbaac143dc --- /dev/null +++ b/absl/random/internal/iostream_state_saver_test.cc @@ -0,0 +1,369 @@ +// 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. + +#include "absl/random/internal/iostream_state_saver.h" + +#include <sstream> +#include <string> + +#include "gtest/gtest.h" + +namespace { + +using absl::random_internal::make_istream_state_saver; +using absl::random_internal::make_ostream_state_saver; +using absl::random_internal::stream_precision_helper; + +template <typename T> +typename absl::enable_if_t<std::is_integral<T>::value, T> // +StreamRoundTrip(T t) { + std::stringstream ss; + { + auto saver = make_ostream_state_saver(ss); + ss.precision(stream_precision_helper<T>::kPrecision); + ss << t; + } + T result = 0; + { + auto saver = make_istream_state_saver(ss); + ss >> result; + } + EXPECT_FALSE(ss.fail()) // + << ss.str() << " " // + << (ss.good() ? "good " : "") // + << (ss.bad() ? "bad " : "") // + << (ss.eof() ? "eof " : "") // + << (ss.fail() ? "fail " : ""); + + return result; +} + +template <typename T> +typename absl::enable_if_t<std::is_floating_point<T>::value, T> // +StreamRoundTrip(T t) { + std::stringstream ss; + { + auto saver = make_ostream_state_saver(ss); + ss.precision(stream_precision_helper<T>::kPrecision); + ss << t; + } + T result = 0; + { + auto saver = make_istream_state_saver(ss); + result = absl::random_internal::read_floating_point<T>(ss); + } + EXPECT_FALSE(ss.fail()) // + << ss.str() << " " // + << (ss.good() ? "good " : "") // + << (ss.bad() ? "bad " : "") // + << (ss.eof() ? "eof " : "") // + << (ss.fail() ? "fail " : ""); + + return result; +} + +TEST(IOStreamStateSaver, BasicSaverState) { + std::stringstream ss; + ss.precision(2); + ss.fill('x'); + ss.flags(std::ios_base::dec | std::ios_base::right); + + { + auto saver = make_ostream_state_saver(ss); + ss.precision(10); + EXPECT_NE('x', ss.fill()); + EXPECT_EQ(10, ss.precision()); + EXPECT_NE(std::ios_base::dec | std::ios_base::right, ss.flags()); + + ss << 1.23; + } + + EXPECT_EQ('x', ss.fill()); + EXPECT_EQ(2, ss.precision()); + EXPECT_EQ(std::ios_base::dec | std::ios_base::right, ss.flags()); +} + +TEST(IOStreamStateSaver, RoundTripInts) { + const uint64_t kUintValues[] = { + 0, + 1, + static_cast<uint64_t>(-1), + 2, + static_cast<uint64_t>(-2), + + 1 << 7, + 1 << 8, + 1 << 16, + 1ull << 32, + 1ull << 50, + 1ull << 62, + 1ull << 63, + + (1 << 7) - 1, + (1 << 8) - 1, + (1 << 16) - 1, + (1ull << 32) - 1, + (1ull << 50) - 1, + (1ull << 62) - 1, + (1ull << 63) - 1, + + static_cast<uint64_t>(-(1 << 8)), + static_cast<uint64_t>(-(1 << 16)), + static_cast<uint64_t>(-(1ll << 32)), + static_cast<uint64_t>(-(1ll << 50)), + static_cast<uint64_t>(-(1ll << 62)), + + static_cast<uint64_t>(-(1 << 8) - 1), + static_cast<uint64_t>(-(1 << 16) - 1), + static_cast<uint64_t>(-(1ll << 32) - 1), + static_cast<uint64_t>(-(1ll << 50) - 1), + static_cast<uint64_t>(-(1ll << 62) - 1), + }; + + for (const uint64_t u : kUintValues) { + EXPECT_EQ(u, StreamRoundTrip<uint64_t>(u)); + + int64_t x = static_cast<int64_t>(u); + EXPECT_EQ(x, StreamRoundTrip<int64_t>(x)); + + double d = static_cast<double>(x); + EXPECT_EQ(d, StreamRoundTrip<double>(d)); + + float f = d; + EXPECT_EQ(f, StreamRoundTrip<float>(f)); + } +} + +TEST(IOStreamStateSaver, RoundTripFloats) { + static_assert( + stream_precision_helper<float>::kPrecision >= 9, + "stream_precision_helper<float>::kPrecision should be at least 9"); + + const float kValues[] = { + 1, + std::nextafter(1.0f, 0.0f), // 1 - epsilon + std::nextafter(1.0f, 2.0f), // 1 + epsilon + + 1.0e+1f, + 1.0e-1f, + 1.0e+2f, + 1.0e-2f, + 1.0e+10f, + 1.0e-10f, + + 0.00000051110000111311111111f, + -0.00000051110000111211111111f, + + 1.234678912345678912345e+6f, + 1.234678912345678912345e-6f, + 1.234678912345678912345e+30f, + 1.234678912345678912345e-30f, + 1.234678912345678912345e+38f, + 1.0234678912345678912345e-38f, + + // Boundary cases. + std::numeric_limits<float>::max(), + std::numeric_limits<float>::lowest(), + std::numeric_limits<float>::epsilon(), + std::nextafter(std::numeric_limits<float>::min(), + 1.0f), // min + epsilon + std::numeric_limits<float>::min(), // smallest normal + // There are some errors dealing with denorms on apple platforms. + std::numeric_limits<float>::denorm_min(), // smallest denorm + std::numeric_limits<float>::min() / 2, + std::nextafter(std::numeric_limits<float>::min(), + 0.0f), // denorm_max + std::nextafter(std::numeric_limits<float>::denorm_min(), 1.0f), + }; + + for (const float f : kValues) { + EXPECT_EQ(f, StreamRoundTrip<float>(f)); + EXPECT_EQ(-f, StreamRoundTrip<float>(-f)); + + double d = f; + EXPECT_EQ(d, StreamRoundTrip<double>(d)); + EXPECT_EQ(-d, StreamRoundTrip<double>(-d)); + + // Avoid undefined behavior (overflow/underflow). + if (d <= std::numeric_limits<int64_t>::max() && + d >= std::numeric_limits<int64_t>::lowest()) { + int64_t x = static_cast<int64_t>(f); + EXPECT_EQ(x, StreamRoundTrip<int64_t>(x)); + } + } +} + +TEST(IOStreamStateSaver, RoundTripDoubles) { + static_assert( + stream_precision_helper<double>::kPrecision >= 17, + "stream_precision_helper<double>::kPrecision should be at least 17"); + + const double kValues[] = { + 1, + std::nextafter(1.0, 0.0), // 1 - epsilon + std::nextafter(1.0, 2.0), // 1 + epsilon + + 1.0e+1, + 1.0e-1, + 1.0e+2, + 1.0e-2, + 1.0e+10, + 1.0e-10, + + 0.00000051110000111311111111, + -0.00000051110000111211111111, + + 1.234678912345678912345e+6, + 1.234678912345678912345e-6, + 1.234678912345678912345e+30, + 1.234678912345678912345e-30, + 1.234678912345678912345e+38, + 1.0234678912345678912345e-38, + + 1.0e+100, + 1.0e-100, + 1.234678912345678912345e+308, + 1.0234678912345678912345e-308, + 2.22507385850720138e-308, + + // Boundary cases. + std::numeric_limits<double>::max(), + std::numeric_limits<double>::lowest(), + std::numeric_limits<double>::epsilon(), + std::nextafter(std::numeric_limits<double>::min(), + 1.0), // min + epsilon + std::numeric_limits<double>::min(), // smallest normal + // There are some errors dealing with denorms on apple platforms. + std::numeric_limits<double>::denorm_min(), // smallest denorm + std::numeric_limits<double>::min() / 2, + std::nextafter(std::numeric_limits<double>::min(), + 0.0), // denorm_max + std::nextafter(std::numeric_limits<double>::denorm_min(), 1.0f), + }; + + for (const double d : kValues) { + EXPECT_EQ(d, StreamRoundTrip<double>(d)); + EXPECT_EQ(-d, StreamRoundTrip<double>(-d)); + + // Avoid undefined behavior (overflow/underflow). + if (d <= std::numeric_limits<float>::max() && + d >= std::numeric_limits<float>::lowest()) { + float f = static_cast<float>(d); + EXPECT_EQ(f, StreamRoundTrip<float>(f)); + } + + // Avoid undefined behavior (overflow/underflow). + if (d <= std::numeric_limits<int64_t>::max() && + d >= std::numeric_limits<int64_t>::lowest()) { + int64_t x = static_cast<int64_t>(d); + EXPECT_EQ(x, StreamRoundTrip<int64_t>(x)); + } + } +} + +TEST(IOStreamStateSaver, RoundTripLongDoubles) { + // Technically, C++ only guarantees that long double is at least as large as a + // double. Practically it varies from 64-bits to 128-bits. + // + // So it is best to consider long double a best-effort extended precision + // type. + + static_assert( + stream_precision_helper<long double>::kPrecision >= 36, + "stream_precision_helper<long double>::kPrecision should be at least 36"); + + using real_type = long double; + const real_type kValues[] = { + 1, + std::nextafter(1.0, 0.0), // 1 - epsilon + std::nextafter(1.0, 2.0), // 1 + epsilon + + 1.0e+1, + 1.0e-1, + 1.0e+2, + 1.0e-2, + 1.0e+10, + 1.0e-10, + + 0.00000051110000111311111111, + -0.00000051110000111211111111, + + 1.2346789123456789123456789123456789e+6, + 1.2346789123456789123456789123456789e-6, + 1.2346789123456789123456789123456789e+30, + 1.2346789123456789123456789123456789e-30, + 1.2346789123456789123456789123456789e+38, + 1.2346789123456789123456789123456789e-38, + 1.2346789123456789123456789123456789e+308, + 1.2346789123456789123456789123456789e-308, + + 1.0e+100, + 1.0e-100, + 1.234678912345678912345e+308, + 1.0234678912345678912345e-308, + + // Boundary cases. + std::numeric_limits<real_type>::max(), + std::numeric_limits<real_type>::lowest(), + std::numeric_limits<real_type>::epsilon(), + std::nextafter(std::numeric_limits<real_type>::min(), + real_type(1)), // min + epsilon + std::numeric_limits<real_type>::min(), // smallest normal + // There are some errors dealing with denorms on apple platforms. + std::numeric_limits<real_type>::denorm_min(), // smallest denorm + std::numeric_limits<real_type>::min() / 2, + std::nextafter(std::numeric_limits<real_type>::min(), + 0.0), // denorm_max + std::nextafter(std::numeric_limits<real_type>::denorm_min(), 1.0f), + }; + + int index = -1; + for (const long double dd : kValues) { + index++; + EXPECT_EQ(dd, StreamRoundTrip<real_type>(dd)) << index; + EXPECT_EQ(-dd, StreamRoundTrip<real_type>(-dd)) << index; + + // Avoid undefined behavior (overflow/underflow). + if (dd <= std::numeric_limits<double>::max() && + dd >= std::numeric_limits<double>::lowest()) { + double d = static_cast<double>(dd); + EXPECT_EQ(d, StreamRoundTrip<double>(d)); + } + + // Avoid undefined behavior (overflow/underflow). + if (dd <= std::numeric_limits<int64_t>::max() && + dd >= std::numeric_limits<int64_t>::lowest()) { + int64_t x = static_cast<int64_t>(dd); + EXPECT_EQ(x, StreamRoundTrip<int64_t>(x)); + } + } +} + +TEST(StrToDTest, DoubleMin) { + const char kV[] = "2.22507385850720138e-308"; + char* end; + double x = std::strtod(kV, &end); + EXPECT_EQ(std::numeric_limits<double>::min(), x); + // errno may equal ERANGE. +} + +TEST(StrToDTest, DoubleDenormMin) { + const char kV[] = "4.94065645841246544e-324"; + char* end; + double x = std::strtod(kV, &end); + EXPECT_EQ(std::numeric_limits<double>::denorm_min(), x); + // errno may equal ERANGE. +} + +} // namespace |