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//
// zug: transducers for C++
// Copyright (C) 2019 Juan Pedro Bolivar Puente
//
// This software is distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt
//
#include <catch2/catch.hpp>
#include <cstdint>
#include <limits>
struct deterministic_engine
{
using result_type = std::uint64_t;
std::uint64_t count = 0;
constexpr static std::uint64_t max()
{
return std::numeric_limits<std::uint64_t>::max();
}
constexpr static std::uint64_t min()
{
return std::numeric_limits<std::uint64_t>::min();
}
std::uint64_t operator()() { return count += max() / 6; }
};
#define ZUG_DEFAULT_RANDOM_ENGINE deterministic_engine
#include <zug/compose.hpp>
#include <zug/transduce.hpp>
#include <zug/transducer/random_sample.hpp>
#include <zug/transducer/range.hpp>
using namespace zug;
TEST_CASE("random_sample, simple")
{
// example1 {
CHECK(transduce(range(20) | random_sample(0.5),
std::plus<>{},
std::size_t{}) == 100);
CHECK(transduce(range(20) | random_sample(1),
std::plus<>{},
std::size_t{}) == 190);
CHECK(transduce(range(20) | random_sample(0), //
std::plus<>{},
std::size_t{}) == 0);
// }
}
TEST_CASE("random_sample, custom generator")
{
auto eng = deterministic_engine{};
auto gen = [eng]() mutable { return double(eng()) * 2 / double(eng.max()); };
CHECK(transduce(comp(range(20), random_sample(0.5, gen)),
std::plus<std::size_t>{},
std::size_t{}) == 36);
CHECK(transduce(comp(range(20), random_sample(1, gen)),
std::plus<std::size_t>{},
std::size_t{}) == 100);
CHECK(transduce(comp(range(20), random_sample(0, gen)),
std::plus<std::size_t>{},
std::size_t{}) == 0);
}
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