std::all_of, std::any_of, std::none_of

Defined in header `<algorithm>`
	(1)
template< class InputIt, class UnaryPredicate > bool all_of( InputIt first, InputIt last, UnaryPredicate p );			(since C++11) (until C++20)
template< class InputIt, class UnaryPredicate > constexpr bool all_of( InputIt first, InputIt last, UnaryPredicate p );			(since C++20)
template< class ExecutionPolicy, class ForwardIt, class UnaryPredicate > bool all_of( ExecutionPolicy&& policy, ForwardIt first, ForwardIt last, UnaryPredicate p );		(2)	(since C++17)
		(3)
template< class InputIt, class UnaryPredicate > bool any_of( InputIt first, InputIt last, UnaryPredicate p );				(since C++11) (until C++20)
template< class InputIt, class UnaryPredicate > constexpr bool any_of( InputIt first, InputIt last, UnaryPredicate p );				(since C++20)
template< class ExecutionPolicy, class ForwardIt, class UnaryPredicate > bool any_of( ExecutionPolicy&& policy, ForwardIt first, ForwardIt last, UnaryPredicate p );			(4)	(since C++17)
			(5)
template< class InputIt, class UnaryPredicate > bool none_of( InputIt first, InputIt last, UnaryPredicate p );					(since C++11) (until C++20)
template< class InputIt, class UnaryPredicate > constexpr bool none_of( InputIt first, InputIt last, UnaryPredicate p );					(since C++20)
template< class ExecutionPolicy, class ForwardIt, class UnaryPredicate > bool none_of( ExecutionPolicy&& policy, ForwardIt first, ForwardIt last, UnaryPredicate p );				(6)	(since C++17)

1) Checks if unary predicate p returns true for all elements in the range [first, last).

3) Checks if unary predicate p returns true for at least one element in the range [first, last).

5) Checks if unary predicate p returns true for no elements in the range [first, last).

2,4,6) Same as (1,3,5), but executed according to policy. These overloads do not participate in overload resolution unless std::is_execution_policy_v<std::decay_t<ExecutionPolicy>> is true

Parameters

first, last	-	the range of elements to examine
policy	-	the execution policy to use. See execution policy for details.
p	-	unary predicate . The signature of the predicate function should be equivalent to the following: bool pred(const Type &a); The signature does not need to have const &, but the function must not modify the objects passed to it. The type Type must be such that an object of type InputIt can be dereferenced and then implicitly converted to Type.
Type requirements
- `InputIt` must meet the requirements of InputIterator.
- `ForwardIt` must meet the requirements of ForwardIterator.
- `UnaryPredicate` must meet the requirements of Predicate.

Return value

1-2) true if unary predicate returns true for all elements in the range, false otherwise. Returns true if the range is empty.

3-4) true if unary predicate returns true for at least one element in the range, false otherwise. Returns false if the range is empty.

5-6) true if unary predicate returns true for no elements in the range, false otherwise. Returns true if the range is empty.

Complexity

1,3,5) At most last - first applications of the predicate

2,4,6) O(last-first) applications of the predicate

Exceptions

The overloads with a template parameter named ExecutionPolicy report errors as follows:

If execution of a function invoked as part of the algorithm throws an exception and ExecutionPolicy is one of the three standard policies, std::terminate is called. For any other ExecutionPolicy, the behavior is implementation-defined.
If the algorithm fails to allocate memory, std::bad_alloc is thrown.

Possible implementation

First version
template< class InputIt, class UnaryPredicate > constexpr bool all_of(InputIt first, InputIt last, UnaryPredicate p) { return std::find_if_not(first, last, p) == last; }
Second version
template< class InputIt, class UnaryPredicate > constexpr bool any_of(InputIt first, InputIt last, UnaryPredicate p) { return std::find_if(first, last, p) != last; }
Third version
template< class InputIt, class UnaryPredicate > constexpr bool none_of(InputIt first, InputIt last, UnaryPredicate p) { return std::find_if(first, last, p) == last; }

Example

Run this code

#include <vector>
#include <numeric>
#include <algorithm>
#include <iterator>
#include <iostream>
#include <functional>

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

    if (std::all_of(v.cbegin(), v.cend(), [](int i){ return i % 2 == 0; })) {
        std::cout << "All numbers are even\n";
    }
    if (std::none_of(v.cbegin(), v.cend(), 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 (std::any_of(v.cbegin(), v.cend(), 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

Language
Headers
Freestanding and hosted implementations
Named requirements
Language support library
Concepts library (C++20)
Diagnostics library
Utilities library
Strings library
Containers library
Algorithms library
Iterators library
Numerics library
Input/output library
Localizations library
Regular expressions library (C++11)
Atomic operations library (C++11)
Thread support library (C++11)
Filesystem library (C++17)
Technical Specifications