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

From cppreference.com
< cpp‎ | algorithm
 
 
Algorithm library
Constrained algorithms and algorithms on ranges (C++20)
Constrained algorithms, e.g. ranges::copy, ranges::sort, ...
Execution policies (C++17)
Non-modifying sequence operations
Batch operations
(C++17)
Search operations
all_ofany_ofnone_of
(C++11)                (C++11)(C++11)

Modifying sequence operations
Copy operations
(C++11)
(C++11)
Swap operations
Transformation operations
Generation operations
Removing operations
Order-changing operations
(until C++17)(C++11)
(C++20)(C++20)
Sampling operations
(C++17)

Sorting and related operations
Partitioning operations
Sorting operations
Binary search operations
(on partitioned ranges)
Set operations (on sorted ranges)
Merge operations (on sorted ranges)
Heap operations
Minimum/maximum operations
(C++11)
(C++17)
Lexicographical comparison operations
Permutation operations
C library
Numeric operations
Operations on uninitialized memory
 
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 [firstlast).
3) Checks if unary predicate p returns true for at least one element in the range [firstlast).
5) Checks if unary predicate p returns true for no elements in the range [firstlast).
2,4,6) Same as (1,3,5), but executed according to policy.
These overloads participate in overload resolution only if

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)

Contents

[edit] Parameters

first, last - the range of elements to examine
policy - the execution policy to use. See execution policy for details.
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.

[edit] Return value

Has true element Yes No
 Has false element  Yes No Yes No
all_of false true false true
any_of true true   false     false  
none_of   false     false   true true

[edit] Complexity

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

[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 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.

[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

#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

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