// Copyright Catch2 Authors
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.txt or copy at
// https://www.boost.org/LICENSE_1_0.txt)
// SPDX-License-Identifier: BSL-1.0
#include <catch2/catch_test_macros.hpp>
#include <catch2/catch_template_test_macros.hpp>
#include <catch2/internal/catch_floating_point_helpers.hpp>
#include <catch2/internal/catch_random_integer_helpers.hpp>
#include <catch2/internal/catch_random_number_generator.hpp>
#include <catch2/internal/catch_random_seed_generation.hpp>
#include <catch2/internal/catch_uniform_floating_point_distribution.hpp>
#include <catch2/internal/catch_uniform_integer_distribution.hpp>
#include <catch2/generators/catch_generators.hpp>
#include <catch2/matchers/catch_matchers_range_equals.hpp>
#include <random>
TEST_CASE("Our PCG implementation provides expected results for known seeds", "[rng]") {
Catch::SimplePcg32 rng;
SECTION("Default seeded") {
REQUIRE(rng() == 0xfcdb943b);
REQUIRE(rng() == 0x6f55b921);
REQUIRE(rng() == 0x4c17a916);
REQUIRE(rng() == 0x71eae25f);
REQUIRE(rng() == 0x6ce7909c);
}
SECTION("Specific seed") {
rng.seed(0xabcd1234);
REQUIRE(rng() == 0x57c08495);
REQUIRE(rng() == 0x33c956ac);
REQUIRE(rng() == 0x2206fd76);
REQUIRE(rng() == 0x3501a35b);
REQUIRE(rng() == 0xfdffb30f);
// Also check repeated output after reseeding
rng.seed(0xabcd1234);
REQUIRE(rng() == 0x57c08495);
REQUIRE(rng() == 0x33c956ac);
REQUIRE(rng() == 0x2206fd76);
REQUIRE(rng() == 0x3501a35b);
REQUIRE(rng() == 0xfdffb30f);
}
}
TEST_CASE("Comparison ops", "[rng]") {
using Catch::SimplePcg32;
REQUIRE(SimplePcg32{} == SimplePcg32{});
REQUIRE(SimplePcg32{ 0 } != SimplePcg32{});
REQUIRE_FALSE(SimplePcg32{ 1 } == SimplePcg32{ 2 });
REQUIRE_FALSE(SimplePcg32{ 1 } != SimplePcg32{ 1 });
}
TEST_CASE("Random seed generation reports unknown methods", "[rng][seed]") {
REQUIRE_THROWS(Catch::generateRandomSeed(static_cast<Catch::GenerateFrom>(77)));
}
TEST_CASE("Random seed generation accepts known methods", "[rng][seed]") {
using Catch::GenerateFrom;
const auto method = GENERATE(
GenerateFrom::Time,
GenerateFrom::RandomDevice,
GenerateFrom::Default
);
REQUIRE_NOTHROW(Catch::generateRandomSeed(method));
}
TEMPLATE_TEST_CASE("uniform_floating_point_distribution never returns infs from finite range",
"[rng][distribution][floating-point][approvals]", float, double) {
std::random_device rd{};
Catch::SimplePcg32 pcg( rd() );
Catch::uniform_floating_point_distribution<TestType> dist(
-std::numeric_limits<TestType>::max(),
std::numeric_limits<TestType>::max() );
for (size_t i = 0; i < 10'000; ++i) {
auto ret = dist( pcg );
REQUIRE_FALSE( std::isinf( ret ) );
REQUIRE_FALSE( std::isnan( ret ) );
}
}
TEST_CASE( "fillBitsFrom - shortening and stretching", "[rng][approvals]" ) {
using Catch::Detail::fillBitsFrom;
// The seed is not important, but the numbers below have to be repeatable.
// They should also exhibit the same general pattern of being prefixes
Catch::SimplePcg32 pcg( 0xaabb'ccdd );
SECTION( "Shorten to 8 bits" ) {
// We cast the result to avoid dealing with char-like type in uint8_t
auto shortened = static_cast<uint32_t>( fillBitsFrom<uint8_t>( pcg ) );
REQUIRE( shortened == 0xcc );
}
SECTION( "Shorten to 16 bits" ) {
auto shortened = fillBitsFrom<uint16_t>( pcg );
REQUIRE( shortened == 0xccbe );
}
SECTION( "Keep at 32 bits" ) {
auto n = fillBitsFrom<uint32_t>( pcg );
REQUIRE( n == 0xccbe'5f04 );
}
SECTION( "Stretch to 64 bits" ) {
auto stretched = fillBitsFrom<uint64_t>( pcg );
REQUIRE( stretched == 0xccbe'5f04'a424'a486 );
}
}
TEST_CASE("uniform_integer_distribution can return the bounds", "[rng][distribution]") {
Catch::uniform_integer_distribution<int32_t> dist( -10, 10 );
REQUIRE( dist.a() == -10 );
REQUIRE( dist.b() == 10 );
}
namespace {
template <typename T>
static void CheckReturnValue(Catch::uniform_integer_distribution<T>& dist,
Catch::SimplePcg32& rng,
T target) {
REQUIRE( dist.a() == dist.b() );
for (int i = 0; i < 1'000; ++i) {
REQUIRE( dist( rng ) == target );
}
}
}
TEMPLATE_TEST_CASE( "uniform_integer_distribution can handle unit ranges",
"[rng][distribution][approvals]",
unsigned char,
signed char,
char,
uint8_t,
int8_t,
uint16_t,
int16_t,
uint32_t,
int32_t,
uint64_t,
int64_t,
size_t,
ptrdiff_t) {
// We want random seed to sample different parts of the rng state,
// the output is predetermined anyway
std::random_device rd;
auto seed = rd();
CAPTURE( seed );
Catch::SimplePcg32 pcg( seed );
// We check unitary ranges of 3 different values, min for type, max for type,
// some value inbetween just to make sure
SECTION("lowest value") {
constexpr auto lowest = std::numeric_limits<TestType>::min();
Catch::uniform_integer_distribution<TestType> dist( lowest, lowest );
CheckReturnValue( dist, pcg, lowest );
}
SECTION( "highest value" ) {
constexpr auto highest = std::numeric_limits<TestType>::max();
Catch::uniform_integer_distribution<TestType> dist( highest, highest );
CheckReturnValue( dist, pcg, highest );
}
SECTION( "some value" ) {
constexpr auto some = TestType( 42 );
Catch::uniform_integer_distribution<TestType> dist( some, some );
CheckReturnValue( dist, pcg, some );
}
}
// Bool needs its own test because it doesn't have a valid "third" value
TEST_CASE( "uniform_integer_distribution can handle boolean unit ranges",
"[rng][distribution][approvals]" ) {
// We want random seed to sample different parts of the rng state,
// the output is predetermined anyway
std::random_device rd;
auto seed = rd();
CAPTURE( seed );
Catch::SimplePcg32 pcg( seed );
// We check unitary ranges of 3 different values, min for type, max for
// type, some value inbetween just to make sure
SECTION( "lowest value" ) {
Catch::uniform_integer_distribution<bool> dist( false, false );
CheckReturnValue( dist, pcg, false );
}
SECTION( "highest value" ) {
Catch::uniform_integer_distribution<bool> dist( true, true );
CheckReturnValue( dist, pcg, true );
}
}
TEMPLATE_TEST_CASE( "uniform_integer_distribution can handle full width ranges",
"[rng][distribution][approvals]",
unsigned char,
signed char,
char,
uint8_t,
int8_t,
uint16_t,
int16_t,
uint32_t,
int32_t,
uint64_t,
int64_t ) {
// We want random seed to sample different parts of the rng state,
// the output is predetermined anyway
std::random_device rd;
auto seed = rd();
CAPTURE( seed );
Catch::SimplePcg32 pcg( seed );
constexpr auto lowest = std::numeric_limits<TestType>::min();
constexpr auto highest = std::numeric_limits<TestType>::max();
Catch::uniform_integer_distribution<TestType> dist( lowest, highest );
STATIC_REQUIRE( std::is_same<TestType, decltype( dist( pcg ) )>::value );
// We need to do bit operations on the results, so we will have to
// cast them to unsigned type.
using BitType = std::make_unsigned_t<TestType>;
BitType ORs = 0;
BitType ANDs = BitType(-1);
for (int i = 0; i < 100; ++i) {
auto bits = static_cast<BitType>( dist( pcg ) );
ORs |= bits;
ANDs &= bits;
}
// Assuming both our RNG and distribution are unbiased, asking for
// the full range should essentially give us random bit generator.
// Over long run, OR of all the generated values should have all
// bits set to 1, while AND should have all bits set to 0.
// The chance of this test failing for unbiased pipeline is
// 1 / 2**iters, which for 100 iterations is astronomical.
REQUIRE( ORs == BitType( -1 ) );
REQUIRE( ANDs == 0 );
}
namespace {
template <typename T>
struct uniform_integer_test_params;
template <>
struct uniform_integer_test_params<bool> {
static constexpr bool lowest = false;
static constexpr bool highest = true;
// This seems weird, but it is an artifact of the specific seed
static constexpr bool expected[] = { true,
true,
true,
true,
true,
true,
false,
true,
true,
true,
true,
true,
false,
true,
true };
};
template <>
struct uniform_integer_test_params<char> {
static constexpr char lowest = 32;
static constexpr char highest = 126;
static constexpr char expected[] = { 'k',
'\\',
'Z',
'X',
'`',
'Q',
';',
'o',
']',
'T',
'v',
'p',
':',
'S',
't' };
};
template <>
struct uniform_integer_test_params<uint8_t> {
static constexpr uint8_t lowest = 3;
static constexpr uint8_t highest = 123;
static constexpr uint8_t expected[] = { 'c',
'P',
'M',
'J',
'U',
'A',
'%',
'h',
'Q',
'F',
'q',
'i',
'$',
'E',
'o' };
};
template <>
struct uniform_integer_test_params<int8_t> {
static constexpr int8_t lowest = -27;
static constexpr int8_t highest = 73;
static constexpr int8_t expected[] = { '5',
'%',
'#',
' ',
'*',
25,
2,
'9',
'&',
29,
'A',
':',
1,
28,
'?' };
};
template <>
struct uniform_integer_test_params<uint16_t> {
static constexpr uint16_t lowest = 123;
static constexpr uint16_t highest = 33333;
static constexpr uint16_t expected[] = { 26684,
21417,
20658,
19791,
22896,
17433,
9806,
27948,
21767,
18588,
30556,
28244,
9439,
18293,
29949 };
};
template <>
struct uniform_integer_test_params<int16_t> {
static constexpr int16_t lowest = -17222;
static constexpr int16_t highest = 17222;
static constexpr int16_t expected[] = { 10326,
4863,
4076,
3177,
6397,
731,
-7179,
11637,
5226,
1929,
14342,
11944,
-7560,
1623,
13712 };
};
template <>
struct uniform_integer_test_params<uint32_t> {
static constexpr uint32_t lowest = 17222;
static constexpr uint32_t highest = 234234;
static constexpr uint32_t expected[] = { 190784,
156367,
151409,
145743,
166032,
130337,
80501,
199046,
158654,
137883,
216091,
200981,
78099,
135954,
212120 };
};
template <>
struct uniform_integer_test_params<int32_t> {
static constexpr int32_t lowest = -237272;
static constexpr int32_t highest = 234234;
static constexpr int32_t expected[] = { 139829,
65050,
54278,
41969,
86051,
8494,
-99785,
157781,
70021,
24890,
194815,
161985,
-105004,
20699,
186186 };
};
template <>
struct uniform_integer_test_params<uint64_t> {
static constexpr uint64_t lowest = 1234;
static constexpr uint64_t highest = 1234567890;
static constexpr uint64_t expected[] = { 987382749,
763380386,
846572137,
359990258,
804599765,
1131353566,
346324913,
1108760730,
1141693933,
856999148,
879390623,
1149485521,
900556586,
952385958,
807916408 };
};
template <>
struct uniform_integer_test_params<int64_t> {
static constexpr int64_t lowest = -1234567890;
static constexpr int64_t highest = 1234567890;
static constexpr int64_t expected[] = { 740197113,
292191940,
458575608,
-514589122,
374630781,
1028139036,
-541919840,
982953318,
1048819790,
479429651,
524212647,
1064402981,
566544615,
670203462,
381264073 };
};
// We need these definitions for C++14 and earlier, but
// GCC will complain about them in newer C++ standards
#if __cplusplus <= 201402L
constexpr bool uniform_integer_test_params<bool>::expected[];
constexpr char uniform_integer_test_params<char>::expected[];
constexpr uint8_t uniform_integer_test_params<uint8_t>::expected[];
constexpr int8_t uniform_integer_test_params<int8_t>::expected[];
constexpr uint16_t uniform_integer_test_params<uint16_t>::expected[];
constexpr int16_t uniform_integer_test_params<int16_t>::expected[];
constexpr uint32_t uniform_integer_test_params<uint32_t>::expected[];
constexpr int32_t uniform_integer_test_params<int32_t>::expected[];
constexpr uint64_t uniform_integer_test_params<uint64_t>::expected[];
constexpr int64_t uniform_integer_test_params<int64_t>::expected[];
#endif
}
TEMPLATE_TEST_CASE( "uniform_integer_distribution is reproducible",
"[rng][distribution][approvals]",
bool,
char,
uint8_t,
int8_t,
uint16_t,
int16_t,
uint32_t,
int32_t,
uint64_t,
int64_t) {
Catch::SimplePcg32 pcg( 0xaabb'ccdd );
constexpr auto lowest = uniform_integer_test_params<TestType>::lowest;
constexpr auto highest = uniform_integer_test_params<TestType>::highest;
Catch::uniform_integer_distribution<TestType> dist(lowest, highest);
constexpr auto iters = 15;
std::array<TestType, iters> generated;
for (int i = 0; i < iters; ++i) {
generated[i] = dist( pcg );
}
REQUIRE_THAT(generated, Catch::Matchers::RangeEquals(uniform_integer_test_params<TestType>::expected));
}
// The reproducibility tests assume that operations on `float`/`double`
// happen in the same precision as the operated-upon type. This is
// generally true, unless the code is compiled for 32 bit targets without
// SSE2 enabled, in which case the operations are done in the x87 FPU,
// which usually implies doing math in 80 bit floats, and then rounding
// into smaller type when the type is saved into memory. This obviously
// leads to a different answer, than doing the math in the correct precision.
#if ( defined( _MSC_VER ) && _M_IX86_FP < 2 ) || \
( defined( __GNUC__ ) && \
( ( defined( __i386__ ) || defined( __x86_64__ ) ) ) && \
!defined( __SSE2_MATH__ ) )
# define CATCH_TEST_CONFIG_DISABLE_FLOAT_REPRODUCIBILITY_TESTS
#endif
#if !defined( CATCH_TEST_CONFIG_DISABLE_FLOAT_REPRODUCIBILITY_TESTS )
namespace {
template <typename T>
struct uniform_fp_test_params;
template<>
struct uniform_fp_test_params<float> {
// These are exactly representable
static constexpr float lowest = -256.125f;
static constexpr float highest = 385.125f;
// These are just round-trip formatted
static constexpr float expected[] = { 92.56961f,
-23.170044f,
310.81833f,
-53.023132f,
105.03287f,
198.77591f,
-172.72931f,
51.805176f,
-241.10156f,
64.66101f,
212.12509f,
-49.24292f,
-177.1399f,
245.23679f,
173.22421f };
};
template <>
struct uniform_fp_test_params<double> {
// These are exactly representable
static constexpr double lowest = -234582.9921875;
static constexpr double highest = 261238.015625;
// These are just round-trip formatted
static constexpr double expected[] = { 35031.207052832615,
203783.3401838024,
44667.940405848756,
-170100.5877224467,
-222966.7418051684,
127472.72630072923,
-173510.88209096913,
97394.16172239158,
119123.6921592663,
22595.741022785165,
8988.68409120926,
136906.86520606978,
33369.19104222473,
60912.7615841752,
-149060.05936760217 };
};
// We need these definitions for C++14 and earlier, but
// GCC will complain about them in newer C++ standards
#if __cplusplus <= 201402L
constexpr float uniform_fp_test_params<float>::expected[];
constexpr double uniform_fp_test_params<double>::expected[];
#endif
} // namespace
TEMPLATE_TEST_CASE( "uniform_floating_point_distribution is reproducible",
"[rng][distribution][floating-point][approvals]",
float,
double ) {
Catch::SimplePcg32 pcg( 0xaabb'aabb );
const auto lowest = uniform_fp_test_params<TestType>::lowest;
const auto highest = uniform_fp_test_params<TestType>::highest;
Catch::uniform_floating_point_distribution<TestType> dist( lowest, highest );
constexpr auto iters = 15;
std::array<TestType, iters> generated;
for ( int i = 0; i < iters; ++i ) {
generated[i] = dist( pcg );
}
REQUIRE_THAT( generated, Catch::Matchers::RangeEquals( uniform_fp_test_params<TestType>::expected ) );
}
#endif // ^^ float reproducibility tests are enabled
TEMPLATE_TEST_CASE( "uniform_floating_point_distribution can handle unitary ranges",
"[rng][distribution][floating-point][approvals]",
float,
double ) {
std::random_device rd;
auto seed = rd();
CAPTURE( seed );
Catch::SimplePcg32 pcg( seed );
const auto highest = TestType(385.125);
Catch::uniform_floating_point_distribution<TestType> dist( highest,
highest );
constexpr auto iters = 20;
for (int i = 0; i < iters; ++i) {
REQUIRE( Catch::Detail::directCompare( dist( pcg ), highest ) );
}
}