NAME¶

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

Synopsis¶

Defined in header <algorithm>
template< class InputIt, class UnaryPred > (1) (since C++11)
bool all_of( InputIt first, InputIt last, UnaryPred p ); (constexpr since C++20)
template< class ExecutionPolicy, class ForwardIt, class
UnaryPred >

bool all_of( ExecutionPolicy&& policy, (2) (since C++17)

ForwardIt first, ForwardIt last, UnaryPred
p );
template< class InputIt, class UnaryPred > (3) (since C++11)
bool any_of( InputIt first, InputIt last, UnaryPred p ); (constexpr since C++20)
template< class ExecutionPolicy, class ForwardIt, class
UnaryPred >

bool any_of( ExecutionPolicy&& policy, (4) (since C++17)

ForwardIt first, ForwardIt last, UnaryPred
p );
template< class InputIt, class UnaryPred > (since C++11)
bool none_of( InputIt first, InputIt last, UnaryPred p (5) (constexpr since C++20)
);
template< class ExecutionPolicy, class ForwardIt, class
UnaryPred >

bool none_of( ExecutionPolicy&& policy, (6) (since C++17)

ForwardIt first, ForwardIt last, UnaryPred
p );

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 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)

Parameters¶

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

The expression p(v) must be convertible to bool for every argument v
p - 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¶

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

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 in libstdc++ and libc++.
* any_of in libstdc++ and libc++.
* none_of in libstdc++ and libc++.

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¶

// 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

See also¶

ranges::all_of
ranges::any_of checks if a predicate is true for all, any or none of the elements
ranges::none_of in a range
(C++20) (niebloid)
(C++20)
(C++20)