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

//===----------------------------------------------------------------------===//
//
// 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: !c++experimental

// General tests for join_view. This file does not test anything specifically.

#include <algorithm>
#include <cassert>
#include <ranges>
#include <string>
#include <vector>

#include "types.h"

template <class R, class I>
bool isEqual(R& r, I i) {
  for (auto e : r)
    if (e != *i++)
      return false;
  return true;
}

int main(int, char**) {
  {
    int buffer[4][4] = {{1111, 2222, 3333, 4444}, {555, 666, 777, 888}, {99, 1010, 1111, 1212}, {13, 14, 15, 16}};
    int* flattened = reinterpret_cast<int*>(buffer);

    ChildView children[4] = {ChildView(buffer[0]), ChildView(buffer[1]), ChildView(buffer[2]), ChildView(buffer[3])};
    auto jv = std::ranges::join_view(ParentView(children));
    assert(isEqual(jv, flattened));
  }

  {
    std::vector<std::string> vec = {"Hello", ",", " ", "World", "!"};
    std::string check = "Hello, World!";
    std::ranges::join_view jv(vec);
    assert(isEqual(jv, check.begin()));
  }

  {
    // P2328R1 join_view should join all views of ranges
    // join a range of prvalue containers
    std::vector x{1, 2, 3, 4};
    auto y = x | std::views::transform([](auto i) {
               std::vector<int> v(i);
               for (int& ii : v) {
                 ii = i;
               }
               return v;
             });

    std::ranges::join_view jv(y);
    std::vector<int> check{1, 2, 2, 3, 3, 3, 4, 4, 4, 4};
    assert(isEqual(jv, check.begin()));
  }

  return 0;
}