std::ranges::all_of, std::ranges::any_of, std::ranges::none_of
From cppreference.com
| Defined in header <algorithm>
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| Call signature |
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template< std::input_iterator I, std::sentinel_for<I> S,
class Proj = std::identity,
std::indirect_unary_predicate<std::projected<I, Proj>> Pred >
constexpr bool all_of( I first, S last, Pred pred, Proj proj = {} );
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(1) | (since C++20) |
template< ranges::input_range R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred >
constexpr bool all_of( R&& r, Pred pred, Proj proj = {} );
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(2) | (since C++20) |
template< std::input_iterator I, std::sentinel_for<I> S,
class Proj = std::identity,
std::indirect_unary_predicate<std::projected<I, Proj>> Pred >
constexpr bool any_of( I first, S last, Pred pred, Proj proj = {} );
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(3) | (since C++20) |
template< ranges::input_range R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred >
constexpr bool any_of( R&& r, Pred pred, Proj proj = {} );
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(4) | (since C++20) |
template< std::input_iterator I, std::sentinel_for<I> S,
class Proj = std::identity,
std::indirect_unary_predicate<std::projected<I, Proj>> Pred >
constexpr bool none_of( I first, S last, Pred pred, Proj proj = {} );
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(5) | (since C++20) |
template< ranges::input_range R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred >
constexpr bool none_of( R&& r, Pred pred, Proj proj = {} );
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(6) | (since C++20) |
template< /*execution-policy*/ Ep, std::random_access_iterator I,
std::sized_sentinel_for<I> S, class Proj = std::identity,
std::indirect_unary_predicate<std::projected<I, Proj>> Pred >
bool all_of( Ep&& policy, I first, S last, Pred pred, Proj proj = {} );
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(7) | (since C++26) |
template< /*execution-policy*/ Ep,
/*sized-random-access-range*/ R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred >
bool all_of( Ep&& policy, R&& r, Pred pred, Proj proj = {} );
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(8) | (since C++26) |
template< /*execution-policy*/ Ep, std::random_access_iterator I,
std::sized_sentinel_for<I> S, class Proj = std::identity,
std::indirect_unary_predicate<std::projected<I, Proj>> Pred >
bool any_of( Ep&& policy, I first, S last, Pred pred, Proj proj = {} );
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(9) | (since C++26) |
template< /*execution-policy*/ Ep,
/*sized-random-access-range*/ R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred >
bool any_of( Ep&& policy, R&& r, Pred pred, Proj proj = {} );
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(10) | (since C++26) |
template< /*execution-policy*/ Ep, std::random_access_iterator I,
std::sized_sentinel_for<I> S, class Proj = std::identity,
std::indirect_unary_predicate<std::projected<I, Proj>> Pred >
bool none_of( Ep&& policy, I first, S last, Pred pred, Proj proj = {} );
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(11) | (since C++26) |
template< /*execution-policy*/ Ep,
/*sized-random-access-range*/ R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred >
bool none_of( Ep&& policy, R&& r, Pred pred, Proj proj = {} );
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(12) | (since C++26) |
For the definition of /*execution-policy*/, see this page; for the definition of /*sized-random-access-range*/, see this page.
1,2) Checks if unary predicate
pred returns false for at least one element (projected by proj) in the range [first, last) or r.3,4) Checks if unary predicate
pred returns true for at least one element (projected by proj) in the range [first, last) or r.5,6) Checks if unary predicate
pred returns true for none of the elements (projected by proj) in the range [first, last) or r.7-12) Same as (1-6), but executed according to
policy.The function-like entities described on this page are algorithm function objects (informally known as niebloids), that is:
- Explicit template argument lists cannot be specified when calling any of them.
- None of them are visible to argument-dependent lookup.
- When any of them are found by normal unqualified lookup as the name to the left of the function-call operator, argument-dependent lookup is inhibited.
Parameters
| first, last | - | the iterator-sentinel pair defining the range of elements to examine |
| r | - | the range of the elements to examine |
| pred | - | the predicate to be applied to the (projected) elements |
| proj | - | the projection to be applied to the elements |
| policy | - | the execution policy to use |
Return value
Range has some true element
|
Yes | No | ||
|---|---|---|---|---|
Range has some false element
|
Yes | No | Yes | No[1] |
all_of
|
false
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true
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false
|
true
|
any_of
|
true
|
true
|
false
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false
|
none_of
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false
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false
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true
|
true
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- ↑ The range is empty in this case.
Complexity
At most range::distance(first, last) or range::distance(r) applications of pred and the proj.
Possible implementation
| all_of (1,2) |
|---|
struct all_of_fn
{
template<std::input_iterator I, std::sentinel_for<I> S, class Proj = std::identity,
std::indirect_unary_predicate<std::projected<I, Proj>> Pred>
constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
{
return ranges::find_if_not(first, last, std::ref(pred), std::ref(proj)) == last;
}
template<ranges::input_range R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred>
constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
{
return operator()(ranges::begin(r), ranges::end(r),
std::ref(pred), std::ref(proj));
}
template<ranges::forward_range R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred>
constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
{
return operator()(ranges::begin(r),
ranges::next(ranges::begin(r), ranges::end(r)),
std::ref(pred), std::ref(proj));
}
};
inline constexpr all_of_fn all_of;
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| any_of (3,4) |
struct any_of_fn
{
template<std::input_iterator I, std::sentinel_for<I> S, class Proj = std::identity,
std::indirect_unary_predicate<std::projected<I, Proj>> Pred>
constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
{
return ranges::find_if(first, last, std::ref(pred), std::ref(proj)) != last;
}
template<ranges::input_range R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred>
constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
{
return operator()(ranges::begin(r), ranges::end(r),
std::ref(pred), std::ref(proj));
}
template<ranges::forward_range R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred>
constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
{
return operator()(ranges::begin(r),
ranges::next(ranges::begin(r), ranges::end(r)),
std::ref(pred), std::ref(proj));
}
};
inline constexpr any_of_fn any_of;
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| none_of (5,6) |
struct none_of_fn
{
template<std::input_iterator I, std::sentinel_for<I> S, class Proj = std::identity,
std::indirect_unary_predicate<std::projected<I, Proj>> Pred>
constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
{
return ranges::find_if(first, last, std::ref(pred), std::ref(proj)) == last;
}
template<ranges::input_range R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred>
constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
{
return operator()(ranges::begin(r), ranges::end(r),
std::ref(pred), std::ref(proj));
}
template<ranges::forward_range R, class Proj = std::identity,
std::indirect_unary_predicate
<std::projected<ranges::iterator_t<R>, Proj>> Pred>
constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
{
return operator()(ranges::begin(r),
ranges::next(ranges::begin(r), ranges::end(r)),
std::ref(pred), std::ref(proj));
}
};
inline constexpr none_of_fn none_of;
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Example
Run this code
#include <algorithm>
#include <functional>
#include <iostream>
#include <iterator>
#include <numeric>
#include <vector>
namespace ranges = std::ranges;
constexpr bool some_of(auto&& r, auto&& pred) // some but not all
{
return not (ranges::all_of(r, pred) or ranges::none_of(r, pred));
}
constexpr auto w = {1, 2, 3};
static_assert(!some_of(w, [](int x) { return x < 1; }));
static_assert( some_of(w, [](int x) { return x < 2; }));
static_assert(!some_of(w, [](int x) { return x < 4; }));
int main()
{
std::vector<int> v(10, 2);
std::partial_sum(v.cbegin(), v.cend(), v.begin());
std::cout << "Among the numbers: ";
ranges::copy(v, std::ostream_iterator<int>(std::cout, " "));
std::cout << '\n';
if (ranges::all_of(v.cbegin(), v.cend(), [](int i) { return i % 2 == 0; }))
std::cout << "All numbers are even\n";
if (ranges::none_of(v, std::bind(std::modulus<int>(), std::placeholders::_1, 2)))
std::cout << "None of them are odd\n";
auto DivisibleBy = [](int d)
{
return [d](int m) { return m % d == 0; };
};
if (ranges::any_of(v, 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++11)(C++11)(C++11) |
checks if a predicate is true for all, any or none of the elements in a range (function template) |