llvm-project/libcxx/test/std/ranges/range.adaptors/range.join.view/begin.pass.cpp

123 lines
3.9 KiB
C++

//===----------------------------------------------------------------------===//
//
// 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
// UNSUPPORTED: libcpp-no-concepts
// UNSUPPORTED: libcpp-has-no-incomplete-ranges
// constexpr auto begin();
// constexpr auto begin() const;
#include <cassert>
#include <ranges>
#include "test_macros.h"
#include "types.h"
struct NonSimpleParentView : std::ranges::view_base {
ChildView* begin() { return nullptr; }
const ChildView* begin() const;
const ChildView* end() const;
};
struct SimpleParentView : std::ranges::view_base {
const ChildView* begin() const;
const ChildView* end() const;
};
constexpr bool test() {
int buffer[4][4] = {{1111, 2222, 3333, 4444}, {555, 666, 777, 888}, {99, 1010, 1111, 1212}, {13, 14, 15, 16}};
{
ChildView children[4] = {ChildView(buffer[0]), ChildView(buffer[1]), ChildView(buffer[2]), ChildView(buffer[3])};
auto jv = std::ranges::join_view(ParentView{children});
assert(*jv.begin() == 1111);
}
{
CopyableChild children[4] = {CopyableChild(buffer[0], 4), CopyableChild(buffer[1], 0), CopyableChild(buffer[2], 1), CopyableChild(buffer[3], 0)};
auto jv = std::ranges::join_view(ParentView{children});
assert(*jv.begin() == 1111);
}
// Parent is empty.
{
CopyableChild children[4] = {CopyableChild(buffer[0]), CopyableChild(buffer[1]), CopyableChild(buffer[2]), CopyableChild(buffer[3])};
std::ranges::join_view jv(ParentView(children, 0));
assert(jv.begin() == jv.end());
}
// Parent size is one.
{
CopyableChild children[1] = {CopyableChild(buffer[0])};
std::ranges::join_view jv(ParentView(children, 1));
assert(*jv.begin() == 1111);
}
// Parent and child size is one.
{
CopyableChild children[1] = {CopyableChild(buffer[0], 1)};
std::ranges::join_view jv(ParentView(children, 1));
assert(*jv.begin() == 1111);
}
// Parent size is one child is empty
{
CopyableChild children[1] = {CopyableChild(buffer[0], 0)};
std::ranges::join_view jv(ParentView(children, 1));
assert(jv.begin() == jv.end());
}
// Has all empty children.
{
CopyableChild children[4] = {CopyableChild(buffer[0], 0), CopyableChild(buffer[1], 0), CopyableChild(buffer[2], 0), CopyableChild(buffer[3], 0)};
auto jv = std::ranges::join_view(ParentView{children});
assert(jv.begin() == jv.end());
}
// First child is empty, others are not.
{
CopyableChild children[4] = {CopyableChild(buffer[0], 4), CopyableChild(buffer[1], 0), CopyableChild(buffer[2], 0), CopyableChild(buffer[3], 0)};
auto jv = std::ranges::join_view(ParentView{children});
assert(*jv.begin() == 1111);
}
// Last child is empty, others are not.
{
CopyableChild children[4] = {CopyableChild(buffer[0], 4), CopyableChild(buffer[1], 4), CopyableChild(buffer[2], 4), CopyableChild(buffer[3], 0)};
auto jv = std::ranges::join_view(ParentView{children});
assert(*jv.begin() == 1111);
}
{
std::ranges::join_view jv(buffer);
assert(*jv.begin() == 1111);
}
{
const std::ranges::join_view jv(buffer);
assert(*jv.begin() == 1111);
}
// !simple-view<V>
{
std::ranges::join_view<NonSimpleParentView> jv;
static_assert(!std::same_as<decltype(jv.begin()),
decltype(std::as_const(jv).begin())>);
}
// simple-view<V> && is_reference_v<range_reference_t<V>>;
{
std::ranges::join_view<SimpleParentView> jv;
static_assert(std::same_as<decltype(jv.begin()),
decltype(std::as_const(jv).begin())>);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}