Home Original page

From cppreference.com

Defined in header <algorithm>

template< class InputIt, class UnaryPred > bool all_of( InputIt first, InputIt last, UnaryPred p );

 (1) (since C++11)
(constexpr since C++20)

template< class ExecutionPolicy, class ForwardIt, class UnaryPred > bool all_of( ExecutionPolicy&& policy, ForwardIt first, ForwardIt last, UnaryPred p );

 (2) (since C++17)

template< class InputIt, class UnaryPred > bool any_of( InputIt first, InputIt last, UnaryPred p );

 (3) (since C++11)
(constexpr since C++20)

template< class ExecutionPolicy, class ForwardIt, class UnaryPred > bool any_of( ExecutionPolicy&& policy, ForwardIt first, ForwardIt last, UnaryPred p );

 (4) (since C++17)

template< class InputIt, class UnaryPred > bool none_of( InputIt first, InputIt last, UnaryPred p );

 (5) (since C++11)
(constexpr since C++20)

template< class ExecutionPolicy, class ForwardIt, class UnaryPred > bool none_of( ExecutionPolicy&& policy, ForwardIt first, ForwardIt last, UnaryPred 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 none of the elements in the range [first, last).

2,4,6) Same as (1,3,5), but executed according to policy.

These overloads participate in overload resolution only if all following conditions are satisfied:

std::is_execution_policy_v<std::decay_t<ExecutionPolicy>> is true.

(until C++20)

std::is_execution_policy_v<std::remove_cvref_t<ExecutionPolicy>> is true.

(since C++20)

Parameters

first, last - the pair of iterators defining the range of elements to examine
policy - the execution policy to use
p - unary predicate .

The expression p(v) must be convertible to bool for every argument v of type (possibly const) VT, where VT is the value type of InputIt, regardless of value category, and must not modify v. Thus, a parameter type of VT&is not allowed, nor is VT unless for VT a move is equivalent to a copy(since C++11). ​

Type requirements
-InputIt must meet the requirements of LegacyInputIterator.
-ForwardIt must meet the requirements of LegacyForwardIterator.
-UnaryPred must meet the requirements of Predicate.

Return value

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
  1. ↑ The range is empty in this case.

Complexity

1-6) At most std::distance(first, last) applications of the predicate p.

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 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

See also the implementations of

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

Example

#include <algorithm>
#include <functional>
#include <iostream>
#include <iterator>
#include <numeric>
#include <vector>
 
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<>(),
                                                     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

See also