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// 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 <errno.h>
#include <stdio.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 (f <= static_cast<float>(std::numeric_limits<int64_t>::max()) &&
f >= static_cast<float>(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 <= static_cast<double>(std::numeric_limits<int64_t>::max()) &&
d >= static_cast<double>(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 <= static_cast<long double>(std::numeric_limits<int64_t>::max()) &&
dd >=
static_cast<long double>(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