# std::experimental::ranges::all_of, std::experimental::ranges::any_of, std::experimental::ranges::none_of

< cpp‎ | experimental‎ | ranges

定义于头文件 `<experimental/ranges/algorithm>` |  |
template< ranges::InputIterator I, ranges::Sentinel<I> S, class Proj = ranges::identity, ranges::IndirectUnaryPredicate<ranges::projected<I, Proj>> Pred > bool all_of( I first, S last, Pred pred, Proj proj = Proj{} ); | (1) | (范围 TS)
template< ranges::InputRange Rng, class Proj = ranges::identity, ranges::IndirectUnaryPredicate< ranges::projected<ranges::iterator_t<Rng>, Proj> > Pred > bool all_of( Rng&& rng, Pred pred, Proj proj = Proj{} ); | (2) | (范围 TS)
template< ranges::InputIterator I, ranges::Sentinel<I> S, class Proj = ranges::identity, ranges::IndirectUnaryPredicate<ranges::projected<I, Proj>> Pred > bool any_of( I first, S last, Pred pred, Proj proj = Proj{} ); | (3) | (范围 TS)
template< ranges::InputRange Rng, class Proj = ranges::identity, ranges::IndirectUnaryPredicate< ranges::projected<ranges::iterator_t<Rng>, Proj> > Pred > bool any_of( Rng&& rng, Pred pred, Proj proj = Proj{} ); | (4) | (范围 TS)
template< ranges::InputIterator I, ranges::Sentinel<I> S, class Proj = identity, ranges::IndirectUnaryPredicate<ranges::projected<I, Proj>> Pred > bool none_of( I first, S last, Pred pred, Proj proj = Proj{} ); | (5) | (范围 TS)
template< ranges::InputRange Rng, class Proj = ranges::identity, ranges::IndirectUnaryPredicate< ranges::projected<ranges::iterator_t<Rng>, Proj> > Pred > bool none_of( Rng&& rng, Pred pred, Proj proj = Proj{} ); | (6) | (范围 TS)

1) 检查一元谓词 `pred` 是否对范围 `[first, last)` 中的所有元素返回 true 。
3) 检查一元谓词 `pred` 是否对范围 `[first, last)` 中至少一个元素返回 true 。
5) 检查一元谓词 `pred` 是否不对范围 `[first, last)` 中任何元素返回 true 。
2,4,6) 同 (1,3,5) ，但以 `rng` 为源范围，如同使用 `ranges::begin(rng)` 和 `ranges::end(rng)` 。

### 参数

first, last | - | 要检验的元素范围
rng | - | 要检验的元素范围
pred | - | 应用到投影后元素的谓词
proj | - | 应用到元素的投影

### 返回值

1-2) 若 `pred` 对范围中所有元素返回 true 则为 true ，否则为 false 。若范围为空则返回 true 。
3-4) 若 `pred` 对范围中至少一个元素返回 true 则为 true ，否则为 false 。若范围为空则返回 false 。
5-6) 若 `pred` 不对范围中任何元素返回 true 则为 true ，否则为 false 。若范围为空则返回 true 。

### 复杂度

1-6) 至多应用 `last - first` 次谓词，应用 `last - first` 次投影。

### 可能的实现

版本一
    template< ranges::InputIterator I, ranges::Sentinel<I> S, class Proj = ranges::identity,
       ranges::IndirectUnaryPredicate<ranges::projected<I, Proj>> Pred >
    bool all_of( I first, S last, Pred pred, Proj proj = Proj{} )
    {
       return ranges::find_if_not(first, last, std::ref(pred), std::ref(proj)) == last;
    }

    template< ranges::InputRange Rng, class Proj = ranges::identity,
       ranges::IndirectUnaryPredicate<ranges::projected<ranges::iterator_t<Rng>, Proj>> Pred >
    bool all_of( Rng&& rng, Pred pred, Proj proj = Proj{} )
    {
       return ranges::all_of(ranges::begin(rng), ranges::end(rng), std::ref(pred), std::ref(proj));
    }
版本二
    template< ranges::InputIterator I, ranges::Sentinel<I> S, class Proj = ranges::identity,
       ranges::IndirectUnaryPredicate<ranges::projected<I, Proj>> Pred >
    bool any_of( I first, S last, Pred pred, Proj proj = Proj{} )
    {
       return ranges::find_if(first, last, std::ref(pred), std::ref(proj)) != last;
    }

    template< ranges::InputRange Rng, class Proj = ranges::identity,
       ranges::IndirectUnaryPredicate<ranges::projected<ranges::iterator_t<Rng>, Proj>> Pred >
    bool any_of( Rng&& rng, Pred pred, Proj proj = Proj{} )
    {
       return ranges::any_of(ranges::begin(rng), ranges::end(rng), std::ref(pred), std::ref(proj));
    }
版本三
    template< ranges::InputIterator I, ranges::Sentinel<I> S, class Proj = identity,
       ranges::IndirectUnaryPredicate<ranges::projected<I, Proj>> Pred >
    bool none_of( I first, S last, Pred pred, Proj proj = Proj{} )
    {
       return ranges::find_if(first, last, std::ref(pred), std::ref(proj)) == last;
    }

    template< ranges::InputRange Rng, class Proj = ranges::identity,
       ranges::IndirectUnaryPredicate<ranges::projected<ranges::iterator_t<Rng>, Proj>> Pred >
    bool none_of( Rng&& rng, Pred pred, Proj proj = Proj{} )
    {
       return ranges::none_of(ranges::begin(rng), ranges::end(rng), std::ref(pred), std::ref(proj));
    }

### 示例

    #include <vector>
    #include <numeric>
    #include <experimental/ranges/algorithm>
    #include <experimental/ranges/iterator>
    #include <iterator>
    #include <iostream>
    #include <functional>

    namespace ranges = std::experimental::ranges;

    int main()
    {
        std::vector<int> v(10, 2);
        std::partial_sum(v.cbegin(), v.cend(), v.begin());
        std::cout << "Among the numbers: ";
        ranges::copy(v, ranges::ostream_iterator<int>(std::cout, " "));
        std::cout << '\n';

        if (ranges::all_of(v.cbegin(), v.cend(), [](int i){ return i % 2 == 0; })) {
            std::cout << "All numbers are even\n";
        }
        if (ranges::none_of(v, std::bind(std::modulus<int>(), std::placeholders::_1, 2))) {
            std::cout << "None of them are odd\n";
        }
        struct DivisibleBy
        {
            const int d;
            DivisibleBy(int n) : d(n) {}
            bool operator()(int n) const { return n % d == 0; }
        };

        if (ranges::any_of(v, DivisibleBy(7))) {
            std::cout << "At least one number is divisible by 7\n";
        }
    }

输出：

    Among the numbers: 2 4 6 8 10 12 14 16 18 20
    All numbers are even
    None of them are odd
    At least one number is divisible by 7

### 参阅

all_of any_of none_of (C++11)(C++11)(C++11) | 检查谓词是否对范围中所有、任一或无元素为 true (函数模板)