std:: all_of, std:: any_of, std:: none_of
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,
|
(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) |
[
first
,
last
)
.
[
first
,
last
)
.
[
first
,
last
)
.
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. |
p | - |
unary predicate .
The expression
p
(
v
)
must be convertible to
bool
for every argument
|
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
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 otherExecutionPolicy
, 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
(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) |