//===----------------------------------------------------------------------===//
//
// 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
// constexpr auto begin();
// constexpr auto begin() const requires forward_range<View> && forward_range<const View>;
#include <ranges>
#include <cassert>
#include <utility>
#include "test_iterators.h"
#include "test_range.h"
#include "types.h"
template <class View>
concept ConstBeginDisabled = !requires (const View v) {
{ (*v.begin()) };
};
constexpr bool test() {
// non-const: forward_range<View> && simple-view<View> -> outer-iterator<Const = true>
// const: forward_range<View> && forward_range<const View> -> outer-iterator<Const = true>
{
using V = ForwardView;
using P = V;
static_assert(std::ranges::forward_range<V>);
static_assert(std::ranges::forward_range<const V>);
static_assert(simple_view<V>);
static_assert(simple_view<P>);
{
std::ranges::lazy_split_view<V, P> v;
auto it = v.begin();
static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>);
static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>);
}
{
const std::ranges::lazy_split_view<V, P> cv;
auto it = cv.begin();
static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>);
static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>);
}
}
// non-const: forward_range<View> && !simple-view<View> -> outer-iterator<Const = false>
// const: forward_range<View> && forward_range<const View> -> outer-iterator<Const = true>
{
using V = ForwardDiffView;
using P = V;
static_assert(std::ranges::forward_range<V>);
static_assert(std::ranges::forward_range<const V>);
static_assert(!simple_view<V>);
static_assert(!simple_view<P>);
{
std::ranges::lazy_split_view<V, P> v;
auto it = v.begin();
static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>);
static_assert(std::is_same_v<decltype(*(*it).begin()), char&>);
}
{
const std::ranges::lazy_split_view<V, P> cv;
auto it = cv.begin();
static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>);
static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>);
}
}
// non-const: forward_range<View> && !simple-view<View> -> outer-iterator<Const = false>
// const: forward_range<View> && !forward_range<const View> -> disabled
{
using V = ForwardOnlyIfNonConstView;
using P = V;
static_assert(std::ranges::forward_range<V>);
static_assert(!std::ranges::forward_range<const V>);
static_assert(!simple_view<V>);
static_assert(!simple_view<P>);
std::ranges::lazy_split_view<V, P> v;
auto it = v.begin();
static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>);
static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>);
static_assert(ConstBeginDisabled<decltype(v)>);
}
// non-const: forward_range<View> && simple-view<View> && !simple-view<Pattern> -> outer-iterator<Const = false>
// const: forward_range<View> && forward_range<const View> -> outer-iterator<Const = true>
{
using V = ForwardView;
using P = ForwardOnlyIfNonConstView;
static_assert(std::ranges::forward_range<V>);
static_assert(std::ranges::forward_range<const V>);
static_assert(simple_view<V>);
static_assert(!simple_view<P>);
{
std::ranges::lazy_split_view<V, P> v;
auto it = v.begin();
static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>);
static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>);
}
{
const std::ranges::lazy_split_view<V, P> cv;
auto it = cv.begin();
static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>);
static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>);
}
}
// non-const: !forward_range<View> && tiny-range<Pattern> -> outer-iterator<Const = false>
// const: !forward_range<View> -> disabled
{
using V = InputView;
using P = ForwardTinyView;
static_assert(!std::ranges::forward_range<V>);
static_assert(std::ranges::forward_range<P>);
std::ranges::lazy_split_view<V, P> v;
auto it = v.begin();
static_assert(std::is_same_v<decltype(it)::iterator_concept, std::input_iterator_tag>);
static_assert(std::is_same_v<decltype(*(*it).begin()), char&>);
static_assert(ConstBeginDisabled<decltype(v)>);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}