std::all_of, std::any_of, std::none_of
From cppreference.com
                    
                                        
                    
                    
                                                            
                    |   Defined in header  <algorithm>
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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,  | 
(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,  | 
(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,  | 
(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:
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 std::is_execution_policy_v<std::decay_t<ExecutionPolicy>> is true.  | 
(until C++20) | 
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 std::is_execution_policy_v<std::remove_cvref_t<ExecutionPolicy>> is true.  | 
(since C++20) | 
Contents | 
[edit] 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   | 
| Type requirements | ||
 -InputIt must meet the requirements of LegacyInputIterator.
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 -ForwardIt must meet the requirements of LegacyForwardIterator.
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 -UnaryPred must meet the requirements of Predicate.
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[edit] 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 | 
- ↑ The range is empty in this case.
 
[edit] Complexity
[edit] 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 
ExecutionPolicyis one of the standard policies, std::terminate is called. For any otherExecutionPolicy, the behavior is implementation-defined. - If the algorithm fails to allocate memory, std::bad_alloc is thrown.
 
[edit] 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; }  | 
[edit] Example
Run this code
#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
[edit] See also
|   (C++20)(C++20)(C++20)  | 
 checks if a predicate is true for all, any or none of the elements in a range (algorithm function object)  |