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    Standard Library Existence Queries Existence Queries Query

    any_of / all_of / none_of any/all/none_of any/all/none_of

    std::vector<int> v {0,2,9,1,3,8,5,2,9};
    auto const check = [](int x) { return x >= 1 };
    // in subrange (as shown in image):
    cout << all_of (begin(v)+1, begin(v)+7, check);  // true
    cout << any_of (begin(v)+1, begin(v)+7, check);  // true
    cout << none_of(begin(v)+1, begin(v)+7, check);  // false
    // in entire vector:
    cout << all_of (begin(v), end(v), check);  // false
    cout << any_of (begin(v), end(v), check);  // true
    cout << none_of(begin(v), end(v), check);  // false
    std::vector<int> v {0,2,9,1,3,8,5,2,9};
    auto const check = [](int x) { return x >= 1 };
    cout << std::ranges::all_of (v, check);  // false
    cout << std::ranges::any_of (v, check);  // true
    cout << std::ranges::none_of(v, check);  // false

    count #occurences count

    std::vector<int> v {5,2,9,1,3,2,5,2,2,9};
    // count in subrange (as shown in image):
    auto n = count(begin(v)+1, begin(v)+8, 2);  // n = 3
    // count in entire vector:
    auto m = count(begin(v), end(v), 2);  // m = 4
    std::vector<int> v {2,9,1,3,2,5,2};
    cout << std::ranges::count(v, 3);  // 1
    cout << std::ranges::count(v, 2);  // 3
    cout << std::ranges::count(v, 7);  // 0

    count_if#elems(f=true) count_if

    std::vector<int> v {5,4,9,1,3,2,5,6,8,9};
    auto const is_even = [](int x) {   return !(x & 1); };
    // count in subrange (as shown in image):
    auto n = count_if(begin(v)+1, begin(v)+8, is_even);  // n = 3
    // count in entire vector:
    auto m = count_if(begin(v), end(v), is_even);  // m = 4
    std::vector<int> v {4,9,1,3,2,5,6};
    auto const is_even = [](int x) {   return !(x & 1); };
    auto n = std::ranges::count(v, is_even);  // n = 3