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Showing content from http://en.cppreference.com/w/cpp/algorithm/../symbol_index/../algorithm/ranges/all_any_none_of.html below:

std::ranges::all_of, std::ranges::any_of, std::ranges::none_of - cppreference.com

Call signature

(1) (since C++20) (2) (since C++20) (3) (since C++20) (4) (since C++20) (5) (since C++20) (6) (since C++20)

1) Checks if unary predicate pred returns false for at least one element in the range [first, last) (after projecting with the projection proj).

3) Checks if unary predicate pred returns true for at least one element in the range [first, last) (after projecting with the projection proj).

5) Checks if unary predicate pred returns true for none of the elements in the range [first, last) (after projecting with the projection proj).

2,4,6)

Same as

(1,3,5)

, but uses

r

as the source range, as if using

ranges::begin(r)

first

and

ranges::end(r)

last

The function-like entities described on this page are algorithm function objects (informally known as niebloids), that is:

Explicit template argument lists cannot be specified when calling any of them.
None of them are visible to argument-dependent lookup.
When any of them are found by normal unqualified lookup as the name to the left of the function-call operator, argument-dependent lookup is inhibited.

[edit] Parameters first, last - the iterator-sentinel pair defining the range of elements to examine r - the range of the elements to examine pred - predicate to apply to the projected elements proj - projection to apply to the elements [edit] Return value 1,2) true

std::invoke(pred, std::invoke(proj, *i)) != false

for every iterator

i

in the range,

false

otherwise. Returns

true

if the range is empty.

3,4) true

std::invoke(pred, std::invoke(proj, *i)) != false

for at least one iterator

i

in the range,

false

otherwise. Returns

false

if the range is empty.

5,6) true

std::invoke(pred, std::invoke(proj, *i)) == false

for every iterator

i

in the range,

false

otherwise. Returns

true

if the range is empty.

Range has some true element Yes No Range has some false element Yes No Yes No^[1] all_of false true false true any_of true true false false none_of false false true true

â The range is empty in this case.

[edit] Complexity

At most last - first applications of the predicate and the projection.

[edit] Possible implementation all_of (1,2)

struct all_of_fn
{
    template<std::input_iterator I, std::sentinel_for<I> S, class Proj = std::identity,
             std::indirect_unary_predicate<std::projected<I, Proj>> Pred>
    constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
    {
        return ranges::find_if_not(first, last, std::ref(pred), std::ref(proj)) == last;
    }
 
    template<ranges::input_range R, class Proj = std::identity,
             std::indirect_unary_predicate<
                 std::projected<ranges::iterator_t<R>,Proj>> Pred>
    constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
    {
        return operator()(ranges::begin(r), ranges::end(r),
                          std::ref(pred), std::ref(proj));
    }
};
 
inline constexpr all_of_fn all_of;

any_of (3,4)

struct any_of_fn
{
    template<std::input_iterator I, std::sentinel_for<I> S, class Proj = std::identity,
             std::indirect_unary_predicate<std::projected<I, Proj>> Pred>
    constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
    {
        return ranges::find_if(first, last, std::ref(pred), std::ref(proj)) != last;
    }
 
    template<ranges::input_range R, class Proj = std::identity,
             std::indirect_unary_predicate<
                 std::projected<ranges::iterator_t<R>,Proj>> Pred>
    constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
    {
        return operator()(ranges::begin(r), ranges::end(r),
                          std::ref(pred), std::ref(proj));
    }
};
 
inline constexpr any_of_fn any_of;

none_of (5,6)

struct none_of_fn
{
    template<std::input_iterator I, std::sentinel_for<I> S, class Proj = std::identity,
             std::indirect_unary_predicate<std::projected<I, Proj>> Pred>
    constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
    {
        return ranges::find_if(first, last, std::ref(pred), std::ref(proj)) == last;
    }
 
    template<ranges::input_range R, class Proj = std::identity,
             std::indirect_unary_predicate<
                 std::projected<ranges::iterator_t<R>,Proj>> Pred>
    constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
    {
        return operator()(ranges::begin(r), ranges::end(r),
                          std::ref(pred), std::ref(proj));
    }
};
 
inline constexpr none_of_fn none_of;

[edit] Example

#include <algorithm>
#include <functional>
#include <iostream>
#include <iterator>
#include <numeric>
#include <vector>
 
namespace ranges = std::ranges;
 
constexpr bool some_of(auto&& r, auto&& pred) // some but not all
{
    return not (ranges::all_of(r, pred) or ranges::none_of(r, pred));
}
 
constexpr auto w = {1, 2, 3};
static_assert(!some_of(w, [](int x) { return x < 1; }));
static_assert( some_of(w, [](int x) { return x < 2; }));
static_assert(!some_of(w, [](int x) { return x < 4; }));
 
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, std::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";
 
    auto DivisibleBy = [](int d)
    {
        return [d](int m) { return m % d == 0; };
    };
 
    if (ranges::any_of(v, DivisibleBy(7)))
        std::cout << "At least one number is divisible by 7\n";
}

Output:

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

[edit] See also checks if a predicate is true for all, any or none of the elements in a range
(function template) [edit]

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