text: /*
   * Copyright (c) Facebook, Inc. and its affiliates.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <folly/container/Access.h>
  
  #include <array>
  #include <initializer_list>
  #include <vector>
  
  #include <folly/portability/GTest.h>
  
  class AccessTest : public testing::Test {};
  
  TEST_F(AccessTest, size_vector) {
    EXPECT_EQ(3, folly::size(std::vector<int>{1, 2, 3}));
  }
  
  TEST_F(AccessTest, size_array) {
    constexpr auto const a = std::array<int, 3>{{1, 2, 3}};
    constexpr auto const size = folly::size(a);
    EXPECT_EQ(3, size);
  }
  
  TEST_F(AccessTest, size_carray) {
    constexpr int const a[3] = {1, 2, 3};
    constexpr auto const size = folly::size(a);
    EXPECT_EQ(3, size);
  }
  
  TEST_F(AccessTest, size_initializer_list) {
    EXPECT_EQ(3, folly::size({1, 2, 3}));
    EXPECT_EQ(3, folly::size(std::initializer_list<int>{1, 2, 3}));
  }
  
  TEST_F(AccessTest, empty_vector) {
    EXPECT_FALSE(folly::empty(std::vector<int>{1, 2, 3}));
    EXPECT_TRUE(folly::empty(std::vector<int>{}));
  }
  
  TEST_F(AccessTest, empty_array) {
    {
      constexpr auto const a = std::array<int, 3>{{1, 2, 3}};
      constexpr auto const empty = folly::empty(a);
      EXPECT_FALSE(empty);
    }
    {
      constexpr auto const a = std::array<int, 0>{{}};
      constexpr auto const empty = folly::empty(a);
      EXPECT_TRUE(empty);
    }
  }
  
  TEST_F(AccessTest, empty_carray) {
    constexpr int const a[3] = {1, 2, 3};
    constexpr auto const empty = folly::empty(a);
    EXPECT_FALSE(empty);
    //  zero-length arrays are not allowed in the language
  }
  
  TEST_F(AccessTest, empty_initializer_list) {
    EXPECT_FALSE(folly::empty({1, 2, 3}));
    EXPECT_FALSE(folly::empty(std::initializer_list<int>{1, 2, 3}));
    EXPECT_TRUE(folly::empty(std::initializer_list<int>{}));
  }
  
  TEST_F(AccessTest, data_vector) {
    EXPECT_EQ(1, *folly::data(std::vector<int>{1, 2, 3}));
    auto v = std::vector<int>{1, 2, 3};
    *folly::data(v) = 4;
    EXPECT_EQ(4, v[0]);
  }
  
  TEST_F(AccessTest, data_array) {
    constexpr auto const a = std::array<int, 3>{{1, 2, 3}};
    auto const data = folly::data(a); // not constexpr until C++17
    EXPECT_EQ(1, *data);
  }
  
  TEST_F(AccessTest, data_carray) {
    constexpr int const a[3] = {1, 2, 3};
    auto const data = folly::data(a); // not constexpr until C++17
    EXPECT_EQ(1, *data);
  }
  
  TEST_F(AccessTest, data_initializer_list) {
    EXPECT_EQ(1, *folly::data({1, 2, 3}));
    EXPECT_EQ(1, *folly::data(std::initializer_list<int>{1, 2, 3}));
  }
  