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Difference between revisions of "cpp/algorithm/all any none of"

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< cpp‎ | algorithm
(+type reqs)
(Wording update.)
 
(37 intermediate revisions by 16 users not shown)
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−
{{cpp/title| all_of | any_of | none_of}}
+
{{cpp/title|all_of|any_of|none_of}}
 
{{cpp/algorithm/navbar}}
 
{{cpp/algorithm/navbar}}
−
{{ddcl list begin}}
+
{{dcl begin}}
−
{{ddcl list header | algorithm}}
+
{{dcl header|algorithm}}
−
{{ddcl list item | notes={{mark since c++11}} | num=1 |
+
{{dcla|num=1|since=c++11|notes={{mark constexpr since c++20}}|
−
template< class InputIt, class UnaryPredicate >
+
template< class InputIt, class UnaryPred >
−
bool all_of( InputIt first, InputIt last, UnaryPredicate p );
+
bool all_of( InputIt first, InputIt last, UnaryPred p );
 
}}
 
}}
−
{{ddcl list item | notes={{mark since c++11}} | num=2 |
+
{{dcl|since=c++17|num=2|
−
template< class InputIt, class UnaryPredicate >
+
template< class ExecutionPolicy, class ForwardIt, class UnaryPred >
−
bool any_of( InputIt first, InputIt last, UnaryPredicate p );
+
bool all_of( ExecutionPolicy&& policy,
 +
            ForwardIt first, ForwardIt last, UnaryPred p );
 
}}
 
}}
−
{{ddcl list item | notes={{mark since c++11}} | num=3 |
+
{{dcla|num=3|since=c++11|notes={{mark constexpr since c++20}}|
−
template< class InputIt, class UnaryPredicate >
+
template< class InputIt, class UnaryPred >
−
bool none_of( InputIt first, InputIt last, UnaryPredicate p );
+
bool any_of( InputIt first, InputIt last, UnaryPred p );
 
}}
 
}}
−
{{ddcl list end}}
+
{{dcl|num=4|since=c++17|
 +
template< class ExecutionPolicy, class ForwardIt, class UnaryPred >
 +
bool any_of( ExecutionPolicy&& policy,
 +
            ForwardIt first, ForwardIt last, UnaryPred p );
 +
}}
 +
{{dcla|num=5|since=c++11|notes={{mark constexpr since c++20}}|
 +
template< class InputIt, class UnaryPred >
 +
bool none_of( InputIt first, InputIt last, UnaryPred p );
 +
}}
 +
{{dcl|num=6|since=c++17|
 +
template< class ExecutionPolicy, class ForwardIt, class UnaryPred >
 +
bool none_of( ExecutionPolicy&& policy,
 +
              ForwardIt first, ForwardIt last, UnaryPred p );
 +
}}
 +
{{dcl end}}
 +
 
 +
@1@ Checks if unary predicate {{c|p}} returns {{c|true}} for all elements in the range {{range|first|last}}.
  
−
1) Checks if unary predicate {{tt|p}} returns {{c|true}} for all elements in the range {{tt|[first, last)}}.
+
@3@ Checks if unary predicate {{c|p}} returns {{c|true}} for at least one element in the range {{range|first|last}}.
  
−
2) Checks if unary predicate {{tt|p}} returns {{c|true}} for at least one element in the range {{tt|[first, last)}}.
+
@5@ Checks if unary predicate {{c|p}} returns {{c|true}} for no elements in the range {{range|first|last}}.
  
−
3) Checks if unary predicate {{tt|p}} returns {{c|true}} for no elements in the range {{tt|[first, last)}}.
+
@2,4,6@ Same as {{v|1,3,5}}, but executed according to {{c|policy}}.
 +
@@ {{cpp/algorithm/parallel overload precondition|plural=true}}
  
 
===Parameters===
 
===Parameters===
−
{{param list begin}}
+
{{par begin}}
−
{{param list item | first, last | the range of elements to examine}}
+
{{par|first, last|the range of elements to examine}}
−
{{param list pred1 | p | p1=InputIt}}
+
{{par exec pol}}
−
{{param list hreq}}
+
{{par pred1|p|p1=InputIt}}
−
{{param list req concept | InputIt | InputIterator}}
+
{{par hreq}}
−
{{param list end}}
+
{{par req named|InputIt|InputIterator}}
 +
{{par req named|ForwardIt|ForwardIterator}}
 +
{{par req named|UnaryPred|Predicate}}
 +
{{par end}}
  
 
===Return value===
 
===Return value===
−
 
+
{|class="wikitable" style="text-align: center;"
−
1) {{c|true}} if unary predicate returns {{c|true}} for all elements in the range, {{c|false}} otherwise. Returns {{c|true}} if the range is empty.
+
!Has {{c|true}} element
−
 
+
!colspan=2|Yes
−
2) {{c|true}} if unary predicate returns {{c|true}} for at least one element in the range, {{c|false}} otherwise. Returns {{c|false}} if the range is empty.
+
!colspan=2|No
−
 
+
|-
−
3) {{c|true}} if unary predicate returns {{c|true}} for no elements in the range, {{c|false}} otherwise. Returns {{c|true}} if the range is empty.
+
!{{nbsp}}Has {{c|false}} element{{nbsp}}
 +
!Yes
 +
!No
 +
!Yes
 +
!No
 +
|-
 +
|{{tt|all_of}}
 +
|{{c|false}}
 +
|{{c|true}}
 +
|{{c|false}}
 +
|{{c|true}}
 +
|-
 +
|{{tt|any_of}}
 +
|{{c|true}}
 +
|{{c|true}}
 +
|{{nbsp|2}}{{c|false}}{{nbsp|2}}
 +
|{{nbsp|2}}{{c|false}}{{nbsp|2}}
 +
|-
 +
|{{tt|none_of}}
 +
|{{nbsp|2}}{{c|false}}{{nbsp|2}}
 +
|{{nbsp|2}}{{c|false}}{{nbsp|2}}
 +
|{{c|true}}
 +
|{{c|true}}
 +
|}
  
 
===Complexity===
 
===Complexity===
 +
@1-6@ At most {{c|std::distance(first, last)}} applications of the predicate {{c|p}}.
  
−
At most {{tt|last}} - {{tt|first}} applications of the predicate
+
===Exceptions===
 +
{{cpp/algorithm/parallel exceptions reporting behavior|singular=no}}
  
 
===Possible implementation===
 
===Possible implementation===
−
{{eq fun | 1=
+
See also the implementations of
−
template< class InputIt, class UnaryPredicate >
+
* {{tt|all_of}} in [https://github.com/gcc-mirror/gcc/blob/d9375e490072d1aae73a93949aa158fcd2a27018/libstdc%2B%2B-v3/include/bits/stl_algo.h#L508 libstdc++] and [https://github.com/llvm-mirror/libcxx/blob/a12cb9d211019d99b5875b6d8034617cbc24c2cc/include/algorithm#L838 libc++].
−
bool all_of(InputIt first, InputIt last, UnaryPredicate p)
+
* {{tt|any_of}} in [https://github.com/gcc-mirror/gcc/blob/d9375e490072d1aae73a93949aa158fcd2a27018/libstdc%2B%2B-v3/include/bits/stl_algo.h#L541 libstdc++] and [https://github.com/llvm-mirror/libcxx/blob/a12cb9d211019d99b5875b6d8034617cbc24c2cc/include/algorithm#L852 libc++].
 +
* {{tt|none_of}} in [https://github.com/gcc-mirror/gcc/blob/d9375e490072d1aae73a93949aa158fcd2a27018/libstdc%2B%2B-v3/include/bits/stl_algo.h#L523 libstdc++] and [https://github.com/llvm-mirror/libcxx/blob/a12cb9d211019d99b5875b6d8034617cbc24c2cc/include/algorithm#L866 libc++].
 +
{{eq impl
 +
|title1=all_of|ver1=1|1=
 +
template<class InputIt, class UnaryPred>
 +
constexpr bool all_of(InputIt first, InputIt last, UnaryPred p)
 
{
 
{
−
     for (; first != last; ++first) {
+
     return std::find_if_not(first, last, p) == last;
−
        if (!p(*first)) return false;
+
−
    }
+
−
    return true;
+
 
}
 
}
−
| 2=
+
|title2=any_of|ver2=3|2=
−
template< class InputIt, class UnaryPredicate >
+
template<class InputIt, class UnaryPred>
−
bool any_of(InputIt first, InputIt last, UnaryPredicate p)
+
constexpr bool any_of(InputIt first, InputIt last, UnaryPred p)
 
{
 
{
−
     for (; first != last; ++first) {
+
     return std::find_if(first, last, p) != last;
−
        if (p(*first)) return true;
+
−
    }
+
−
    return false;
+
 
}
 
}
−
| 3=
+
|title3=none_of|ver3=5|3=
−
template< class InputIt, class UnaryPredicate >
+
template<class InputIt, class UnaryPred>
−
bool none_of(InputIt first, InputIt last, UnaryPredicate p)
+
constexpr bool none_of(InputIt first, InputIt last, UnaryPred p)
 
{
 
{
−
     for (; first != last; ++first) {
+
     return std::find_if(first, last, p) == last;
−
        if (p(*first)) return false;
+
−
    }
+
−
    return true;
+
 
}
 
}
 
}}
 
}}
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===Example===
 
===Example===
 
{{example
 
{{example
−
| code=#include <vector>
+
|code=
−
#include <numeric>
+
 
#include <algorithm>
 
#include <algorithm>
−
#include <iterator>
 
−
#include <iostream>
 
 
#include <functional>
 
#include <functional>
 +
#include <iostream>
 +
#include <iterator>
 +
#include <numeric>
 +
#include <vector>
 
   
 
   
 
int main()
 
int main()
Line 89: Line 132:
 
     std::copy(v.cbegin(), v.cend(), std::ostream_iterator<int>(std::cout, " "));
 
     std::copy(v.cbegin(), v.cend(), std::ostream_iterator<int>(std::cout, " "));
 
     std::cout << '\n';
 
     std::cout << '\n';
−
+
   
−
     if (std::all_of(v.cbegin(), v.cend(), [](int i){ return i % 2 == 0; })) {
+
     if (std::all_of(v.cbegin(), v.cend(), [](int i) { return i % 2 == 0; }))
 
         std::cout << "All numbers are even\n";
 
         std::cout << "All numbers are even\n";
−
     }
+
      
−
     if (std::none_of(v.cbegin(), v.cend(), std::bind(std::modulus<int>(),  
+
     if (std::none_of(v.cbegin(), v.cend(), std::bind(std::modulus<>(),
−
                                                     std::placeholders::_1, 2))) {
+
                                                     std::placeholders::_1, 2)))
 
         std::cout << "None of them are odd\n";
 
         std::cout << "None of them are odd\n";
−
     }
+
      
 
     struct DivisibleBy
 
     struct DivisibleBy
 
     {
 
     {
Line 103: Line 146:
 
         bool operator()(int n) const { return n % d == 0; }
 
         bool operator()(int n) const { return n % d == 0; }
 
     };
 
     };
−
+
   
−
     if (std::any_of(v.cbegin(), v.cend(), DivisibleBy(7))) {
+
     if (std::any_of(v.cbegin(), v.cend(), DivisibleBy(7)))
 
         std::cout << "At least one number is divisible by 7\n";
 
         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  
+
|output=Among the numbers: 2 4 6 8 10 12 14 16 18 20
 
All numbers are even
 
All numbers are even
 
None of them are odd
 
None of them are odd
Line 114: Line 156:
 
}}
 
}}
  
−
[[ja:cpp/algorithm/all any none of]]
+
===See also===
 +
{{dsc begin}}
 +
{{dsc inc|cpp/algorithm/ranges/dsc all_any_none_of}}
 +
{{dsc end}}
 +
 
 +
{{langlinks|de|es|fr|it|ja|pt|ru|zh}}

Latest revision as of 01:47, 19 March 2024

 
C++
 
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)
(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
(C++20)
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 [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)

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

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
(niebloid)[edit]
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