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// { dg-do run { target c++23 } }
// { dg-add-options no_pch }
#include <algorithm>
#if __cpp_lib_ranges_fold != 202207L
# error "Feature-test macro __cpp_lib_ranges_fold has wrong value in <algorithm>"
#endif
#include <ranges>
#include <testsuite_iterators.h>
namespace ranges = std::ranges;
namespace views = std::views;
constexpr bool
test01()
{
int x[] = {1, 2, 3, 4, 5};
auto f = [](int&& acc, int& x) {
return 2 * acc + x;
};
VERIFY( ranges::fold_left(x, 0, f) == 57 );
VERIFY( ranges::fold_left(x, 1, f) == 89 );
VERIFY( ranges::fold_left(x+0, x+0, 1, f) == 1 );
VERIFY( ranges::fold_left_first(x, f).value() == 57 );
VERIFY( !ranges::fold_left_first(x+0, x+0, f).has_value() );
return true;
}
void
test02()
{
int x[] = {1, 2, 3, 4, 5};
auto f = [](int&& acc, int& x) {
return 2 * acc + x;
};
__gnu_test::test_input_range<int> rx(x);
ranges::in_value_result ivr = ranges::fold_left_with_iter(rx, 0, f);
VERIFY( ivr.in == rx.end() );
VERIFY( ivr.value == 57 );
rx.bounds.first = x;
ranges::in_value_result ivr2 = ranges::fold_left_first_with_iter(rx, f);
VERIFY( ivr2.in == rx.end() );
VERIFY( ivr2.value.value() == 57 );
rx.bounds.first = x;
auto v = rx | views::take(0);
ranges::in_value_result ivr3 = ranges::fold_left_first_with_iter(v, f);
VERIFY( ivr3.in == v.end() );
VERIFY( !ivr3.value.has_value() );
}
constexpr bool
test03()
{
double x[] = {0.5, 0.25, 0.125, 0.125};
VERIFY( ranges::fold_left(x, 0, std::plus{}) == 1.0 );
VERIFY( ranges::fold_left_with_iter(x, 0, std::plus{}).value == 1.0 );
return true;
}
int
main()
{
static_assert(test01());
test02();
static_assert(test03());
}
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