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// Range v3 library
//
// Copyright Eric Niebler 2014-present
//
// Use, modification and distribution is subject to the
// Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// Project home: https://github.com/ericniebler/range-v3
//
//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include <cmath>
#include <functional>
#include <range/v3/algorithm/fold.hpp>
#include <range/v3/algorithm/min.hpp>
#include <range/v3/core.hpp>
#include "../simple_test.hpp"
#include "../test_iterators.hpp"
struct Approx
{
double value;
Approx(double v)
: value(v)
{}
friend bool operator==(Approx a, double d)
{
return std::fabs(a.value - d) < 0.001;
}
friend bool operator==(double d, Approx a)
{
return a == d;
}
};
template<class Iter, class Sent = Iter>
void test_left()
{
double da[] = {0.25, 0.75};
CHECK(ranges::fold_left(Iter(da), Sent(da), 1, std::plus<>()) == Approx{1.0});
CHECK(ranges::fold_left(Iter(da), Sent(da + 2), 1, std::plus<>()) == Approx{2.0});
CHECK(ranges::fold_left_first(Iter(da), Sent(da), ranges::min) == ranges::nullopt);
CHECK(ranges::fold_left_first(Iter(da), Sent(da + 2), ranges::min) ==
ranges::optional<Approx>(0.25));
using ranges::make_subrange;
CHECK(ranges::fold_left(make_subrange(Iter(da), Sent(da)), 1, std::plus<>()) ==
Approx{1.0});
CHECK(ranges::fold_left(make_subrange(Iter(da), Sent(da + 2)), 1, std::plus<>()) ==
Approx{2.0});
CHECK(ranges::fold_left_first(make_subrange(Iter(da), Sent(da)), ranges::min) ==
ranges::nullopt);
CHECK(ranges::fold_left_first(make_subrange(Iter(da), Sent(da + 2)), ranges::min) ==
ranges::optional<Approx>(0.25));
}
void test_right()
{
double da[] = {0.25, 0.75};
CHECK(ranges::fold_right(da, da + 2, 1, std::plus<>()) == Approx{2.0});
CHECK(ranges::fold_right(da, 1, std::plus<>()) == Approx{2.0});
// f(0.25, f(0.75, 1))
CHECK(ranges::fold_right(da, da + 2, 1, std::minus<>()) == Approx{0.5});
CHECK(ranges::fold_right(da, 1, std::minus<>()) == Approx{0.5});
int xs[] = {1, 2, 3};
auto concat = [](int i, std::string s) { return s + std::to_string(i); };
CHECK(ranges::fold_right(xs, xs + 2, std::string(), concat) == "21");
CHECK(ranges::fold_right(xs, std::string(), concat) == "321");
}
int main()
{
test_left<InputIterator<const double *>>();
test_left<ForwardIterator<const double *>>();
test_left<BidirectionalIterator<const double *>>();
test_left<RandomAccessIterator<const double *>>();
test_left<const double *>();
test_left<InputIterator<const double *>, Sentinel<const double *>>();
test_left<ForwardIterator<const double *>, Sentinel<const double *>>();
test_left<BidirectionalIterator<const double *>, Sentinel<const double *>>();
test_left<RandomAccessIterator<const double *>, Sentinel<const double *>>();
test_right();
return ::test_result();
}
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