C++ ranges::make_span方法代码示例

本文整理汇总了C++中ranges::make_span方法的典型用法代码示例。如果您正苦于以下问题：C++ ranges::make_span方法的具体用法？C++ ranges::make_span怎么用？C++ ranges::make_span使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类ranges的用法示例。

在下文中一共展示了ranges::make_span方法的6个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: test_case_from_pointer_pointer_constructor

void test_case_from_pointer_pointer_constructor()
{
    int arr[4] = {1, 2, 3, 4};

    {
        span<int> s{&arr[0], &arr[2]};
        CHECK((s.size() == 2 && s.data() == &arr[0]));
        CHECK((s[0] == 1 && s[1] == 2));
    }

    {
        span<int, 2> s{&arr[0], &arr[2]};
        CHECK((s.size() == 2 && s.data() == &arr[0]));
        CHECK((s[0] == 1 && s[1] == 2));
    }

    {
        span<int> s{&arr[0], &arr[0]};
        CHECK((s.size() == 0 && s.data() == &arr[0]));
    }

    {
        span<int, 0> s{&arr[0], &arr[0]};
        CHECK((s.size() == 0 && s.data() == &arr[0]));
    }

    {
        int* p = nullptr;
        span<int> s{p, p};
        CHECK((s.size() == 0 && s.data() == nullptr));
    }

    {
        int* p = nullptr;
        span<int, 0> s{p, p};
        CHECK((s.size() == 0 && s.data() == nullptr));
    }

    {
        auto s = make_span(&arr[0], &arr[2]);
        CHECK((s.size() == 2 && s.data() == &arr[0]));
        CHECK((s[0] == 1 && s[1] == 2));
    }

    {
        auto s = make_span(&arr[0], &arr[0]);
        CHECK((s.size() == 0 && s.data() == &arr[0]));
    }

    {
        int* p = nullptr;
        auto s = make_span(p, p);
        CHECK((s.size() == 0 && s.data() == nullptr));
    }
}

开发者ID:gnzlbg，项目名称:range-v3，代码行数:55，代码来源:span.cpp

示例2: test_case_from_array_constructor

void test_case_from_array_constructor()
{
    int arr[5] = {1, 2, 3, 4, 5};

    {
        span<int> s{arr};
        CHECK((s.size() == 5 && s.data() == &arr[0]));
    }

    {
        span<int, 5> s{arr};
        CHECK((s.size() == 5 && s.data() == &arr[0]));
    }

    int arr2d[2][3] = {1, 2, 3, 4, 5, 6};

    CONCEPT_ASSERT(!std::is_constructible<span<int, 6>, int(&)[5]>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<int, 0>, int(&)[5]>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<int>, decltype((arr2d))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<int, 0>, decltype((arr2d))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<int, 6>, decltype((arr2d))>::value);

    {
        span<int[3]> s{&(arr2d[0]), 1};
        CHECK((s.size() == 1 && s.data() == &arr2d[0]));
    }

    int arr3d[2][3][2] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};

    CONCEPT_ASSERT(!std::is_constructible<span<int>, decltype((arr3d))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<int, 0>, decltype((arr3d))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<int, 11>, decltype((arr3d))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<int, 12>, decltype((arr3d))>::value);

    {
        span<int[3][2]> s{&arr3d[0], 1};
        CHECK((s.size() == 1 && s.data() == &arr3d[0]));
    }

    {
        auto s = make_span(arr);
        CHECK((s.size() == 5 && s.data() == &arr[0]));
    }

    {
        auto s = make_span(&(arr2d[0]), 1);
        CHECK((s.size() == 1 && s.data() == &arr2d[0]));
    }

    {
        auto s = make_span(&arr3d[0], 1);
        CHECK((s.size() == 1 && s.data() == &arr3d[0]));
    }
}

开发者ID:gnzlbg，项目名称:range-v3，代码行数:54，代码来源:span.cpp

示例3: test_case_from_const_std_array_constructor

void test_case_from_const_std_array_constructor()
{
    const std::array<int, 4> arr = {1, 2, 3, 4};

    {
        span<const int> s{arr};
        CHECK((s.size() == narrow_cast<std::ptrdiff_t>(arr.size()) && s.data() == arr.data()));
    }

    {
        span<const int, 4> s{arr};
        CHECK((s.size() == narrow_cast<std::ptrdiff_t>(arr.size()) && s.data() == arr.data()));
    }

    CONCEPT_ASSERT(!std::is_constructible<span<const int, 2>, decltype((arr))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<const int, 0>, decltype((arr))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<const int, 5>, decltype((arr))>::value);

    {
        auto get_an_array = []() -> const std::array<int, 4> { return {1, 2, 3, 4}; };
        auto take_a_span = [](span<const int>) {};
        take_a_span(get_an_array());
    }

    {
        auto s = make_span(arr);
        CHECK((s.size() == narrow_cast<std::ptrdiff_t>(arr.size()) && s.data() == arr.data()));
    }
}

开发者ID:gnzlbg，项目名称:range-v3，代码行数:29，代码来源:span.cpp

示例4: test_case_from_pointer_size_constructor

void test_case_from_pointer_size_constructor()
{
    int arr[4] = {1, 2, 3, 4};

    {
        span<int> s{&arr[0], 2};
        CHECK((s.size() == 2 && s.data() == &arr[0]));
        CHECK((s[0] == 1 && s[1] == 2));
    }

    {
        span<int, 2> s{&arr[0], 2};
        CHECK((s.size() == 2 && s.data() == &arr[0]));
        CHECK((s[0] == 1 && s[1] == 2));
    }

    {
        int* p = nullptr;
        span<int> s{p, static_cast<span<int>::index_type>(0)};
        CHECK((s.size() == 0 && s.data() == nullptr));
    }

    {
        auto s = make_span(&arr[0], 2);
        CHECK((s.size() == 2 && s.data() == &arr[0]));
        CHECK((s[0] == 1 && s[1] == 2));
    }

    {
        int* p = nullptr;
        auto s = make_span(p, static_cast<span<int>::index_type>(0));
        CHECK((s.size() == 0 && s.data() == nullptr));
    }

    {
        int i = 42;
        span<int> s{&i, 0};
        CHECK((s.size() == 0 && s.data() == &i));

        span<const int> cs{&i, 0};
        CHECK((s.size() == 0 && s.data() == &i));
    }
}

开发者ID:gnzlbg，项目名称:range-v3，代码行数:43，代码来源:span.cpp

示例5: test_case_from_std_array_const_constructor

void test_case_from_std_array_const_constructor()
{
    std::array<const int, 4> arr = {1, 2, 3, 4};

    {
        span<const int> s{arr};
        CHECK((s.size() == narrow_cast<std::ptrdiff_t>(arr.size()) && s.data() == arr.data()));
    }

    {
        span<const int, 4> s{arr};
        CHECK((s.size() == narrow_cast<std::ptrdiff_t>(arr.size()) && s.data() == arr.data()));
    }

    CONCEPT_ASSERT(!std::is_constructible<span<const int, 2>, decltype((arr))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<const int, 0>, decltype((arr))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<const int, 5>, decltype((arr))>::value);
    CONCEPT_ASSERT(!std::is_constructible<span<int, 4>, decltype((arr))>::value);

    {
        auto s = make_span(arr);
        CHECK((s.size() == narrow_cast<std::ptrdiff_t>(arr.size()) && s.data() == arr.data()));
    }
}

开发者ID:gnzlbg，项目名称:range-v3，代码行数:24，代码来源:span.cpp

示例6: test_case_from_container_constructor

void test_case_from_container_constructor()
{
    std::vector<int> v = {1, 2, 3};
    const std::vector<int> cv = v;

    {
        span<int> s{v};
        CHECK((s.size() == narrow_cast<std::ptrdiff_t>(v.size()) && s.data() == v.data()));

        span<const int> cs{v};
        CHECK((cs.size() == narrow_cast<std::ptrdiff_t>(v.size()) && cs.data() == v.data()));
    }

    std::string str = "hello";
    const std::string cstr = "hello";

    {
        span<char> s{str};
        CHECK((s.size() == narrow_cast<std::ptrdiff_t>(str.size()) && s.data() == str.data()));
    }

    {
        auto get_temp_string = []() -> std::string { return {}; };
        auto use_span = [](span<char>) {};
        use_span(get_temp_string());
    }

    {
        span<const char> cs{str};
        CHECK((cs.size() == narrow_cast<std::ptrdiff_t>(str.size()) && cs.data() == str.data()));
    }

    {
        auto get_temp_string = []() -> std::string { return {}; };
        auto use_span = [](span<const char>) {};
        use_span(get_temp_string());
    }

    {
        CONCEPT_ASSERT(!std::is_constructible<span<char>, decltype((cstr))>::value);
        span<const char> cs{cstr};
        CHECK((cs.size() == narrow_cast<std::ptrdiff_t>(cstr.size()) &&
              cs.data() == cstr.data()));
    }

    {
        auto get_temp_vector = []() -> std::vector<int> { return {}; };
        auto use_span = [](span<int>) {};
        use_span(get_temp_vector());
    }

    {
        auto get_temp_vector = []() -> std::vector<int> { return {}; };
        auto use_span = [](span<const int>) {};
        use_span(get_temp_vector());
    }

    CONCEPT_ASSERT(!std::is_convertible<const std::vector<int>, span<const char>>::value);

    {
        auto get_temp_string = []() -> const std::string { return {}; };
        auto use_span = [](span<const char> s) { static_cast<void>(s); };
        use_span(get_temp_string());
    }

    CONCEPT_ASSERT(!std::is_constructible<span<int>, std::map<int, int>&>::value);

    {
        auto s = make_span(v);
        CHECK((s.size() == narrow_cast<std::ptrdiff_t>(v.size()) && s.data() == v.data()));

        auto cs = make_span(cv);
        CHECK((cs.size() == narrow_cast<std::ptrdiff_t>(cv.size()) && cs.data() == cv.data()));
    }
}

开发者ID:gnzlbg，项目名称:range-v3，代码行数:75，代码来源:span.cpp

注：本文中的ranges::make_span方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。