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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// template <input_range Range>
// requires constructible_from<View, views::all_t<Range>> &&
// constructible_from<Pattern, single_view<range_value_t<Range>>>
// constexpr split_view(Range&& r, range_value_t<Range> e);
#include <algorithm>
#include <cassert>
#include <ranges>
#include <string>
#include <string_view>
#include <type_traits>
#include <utility>
struct Counting {
int* times_copied = nullptr;
int* times_moved = nullptr;
constexpr Counting(int& copies_ctr, int& moves_ctr) : times_copied(&copies_ctr), times_moved(&moves_ctr) {}
constexpr Counting(const Counting& rhs) : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {
++(*times_copied);
}
constexpr Counting(Counting&& rhs) : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {
++(*times_moved);
}
constexpr Counting& operator=(const Counting&) = default;
constexpr Counting& operator=(Counting&&) = default;
};
struct ElementWithCounting : Counting {
using Counting::Counting;
constexpr bool operator==(const ElementWithCounting&) const { return true; }
};
struct RangeWithCounting : Counting {
using Counting::Counting;
constexpr const ElementWithCounting* begin() const { return nullptr; }
constexpr const ElementWithCounting* end() const { return nullptr; }
constexpr bool operator==(const RangeWithCounting&) const { return true; }
};
static_assert(std::ranges::forward_range<RangeWithCounting>);
static_assert(!std::ranges::view<RangeWithCounting>);
struct StrView : std::ranges::view_base {
std::string buffer_;
template <std::ranges::range R>
constexpr StrView(R&& r) : buffer_(std::ranges::begin(r), std::ranges::end(r)) {}
constexpr const char* begin() const { return buffer_.data(); }
constexpr const char* end() const { return buffer_.data() + buffer_.size(); }
constexpr bool operator==(const StrView& rhs) const { return buffer_ == rhs.buffer_; }
};
static_assert(std::ranges::random_access_range<StrView>);
static_assert(std::ranges::view<StrView>);
static_assert(std::is_copy_constructible_v<StrView>);
constexpr bool test() {
{
using V = std::ranges::split_view<StrView, StrView>;
// Calling the constructor with `(std::string, range_value_t)`.
{
std::string input("abc def");
V v(input, ' ');
assert(v.base() == input);
assert(std::ranges::equal(*v.begin(), std::string_view("abc")));
}
// Calling the constructor with `(StrView, range_value_t)`.
{
StrView input("abc def");
V v(input, ' ');
assert(v.base() == input);
assert(std::ranges::equal(*v.begin(), std::string_view("abc")));
}
struct Empty {};
static_assert(!std::is_constructible_v<V, Empty, std::string_view>);
static_assert(!std::is_constructible_v<V, std::string_view, Empty>);
}
// Make sure the arguments are moved, not copied.
{
using Range = RangeWithCounting;
using Element = ElementWithCounting;
using Pattern = std::ranges::single_view<Element>;
// Arguments are lvalues.
{
using View = std::ranges::ref_view<Range>;
int range_copied = 0, range_moved = 0, element_copied = 0, element_moved = 0;
Range range(range_copied, range_moved);
Element element(element_copied, element_moved);
std::ranges::split_view<View, Pattern> v(range, element);
assert(range_copied == 0); // `ref_view` does neither copy...
assert(range_moved == 0); // ...nor move the element.
assert(element_copied == 1); // The element is copied into the argument...
assert(element_moved == 1); // ...and moved into the member variable.
}
// Arguments are rvalues.
{
using View = std::ranges::owning_view<Range>;
int range_copied = 0, range_moved = 0, element_copied = 0, element_moved = 0;
std::ranges::split_view<View, Pattern> v(
Range(range_copied, range_moved), Element(element_copied, element_moved));
assert(range_copied == 0);
assert(range_moved == 1); // `owning_view` moves the given argument.
assert(element_copied == 0);
assert(element_moved == 1);
}
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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