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Catch2/src/catch2/generators/catch_generators_random.hpp
2022-06-02 12:15:35 +02:00

99 lines
2.8 KiB
C++

// Copyright Catch2 Authors
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// https://www.boost.org/LICENSE_1_0.txt)
// SPDX-License-Identifier: BSL-1.0
#ifndef CATCH_GENERATORS_RANDOM_HPP_INCLUDED
#define CATCH_GENERATORS_RANDOM_HPP_INCLUDED
#include <catch2/internal/catch_context.hpp>
#include <catch2/generators/catch_generators.hpp>
#include <catch2/internal/catch_random_number_generator.hpp>
#include <random>
namespace Catch {
namespace Generators {
namespace Detail {
// Returns a suitable seed for a random floating generator based off
// the primary internal rng. It does so by taking current value from
// the rng and returning it as the seed.
std::uint32_t getSeed();
}
template <typename Float>
class RandomFloatingGenerator final : public IGenerator<Float> {
Catch::SimplePcg32 m_rng;
std::uniform_real_distribution<Float> m_dist;
Float m_current_number;
public:
RandomFloatingGenerator( Float a, Float b, std::uint32_t seed ):
m_rng(seed),
m_dist(a, b) {
static_cast<void>(next());
}
Float const& get() const override {
return m_current_number;
}
bool next() override {
m_current_number = m_dist(m_rng);
return true;
}
};
template <typename Integer>
class RandomIntegerGenerator final : public IGenerator<Integer> {
Catch::SimplePcg32 m_rng;
std::uniform_int_distribution<Integer> m_dist;
Integer m_current_number;
public:
RandomIntegerGenerator( Integer a, Integer b, std::uint32_t seed ):
m_rng(seed),
m_dist(a, b) {
static_cast<void>(next());
}
Integer const& get() const override {
return m_current_number;
}
bool next() override {
m_current_number = m_dist(m_rng);
return true;
}
};
template <typename T>
std::enable_if_t<std::is_integral<T>::value, GeneratorWrapper<T>>
random(T a, T b) {
static_assert(
!std::is_same<T, char>::value &&
!std::is_same<T, uint8_t>::value &&
!std::is_same<T, uint8_t>::value &&
!std::is_same<T, signed char>::value &&
!std::is_same<T, unsigned char>::value &&
!std::is_same<T, bool>::value,
"The requested type is not supported by the underlying random distributions from std" );
return GeneratorWrapper<T>(
Catch::Detail::make_unique<RandomIntegerGenerator<T>>(a, b, Detail::getSeed())
);
}
template <typename T>
std::enable_if_t<std::is_floating_point<T>::value,
GeneratorWrapper<T>>
random(T a, T b) {
return GeneratorWrapper<T>(
Catch::Detail::make_unique<RandomFloatingGenerator<T>>(a, b, Detail::getSeed())
);
}
} // namespace Generators
} // namespace Catch
#endif // CATCH_GENERATORS_RANDOM_HPP_INCLUDED