# not1 Function

Returns the complement of a unary predicate.

## Syntax

``````template<class UnaryPredicate>
unary_negate<UnaryPredicate> not1(
const UnaryPredicate& _Pred
);
``````

## Parameters

• _Pred
The unary predicate to be negated.

## Return Value

A unary predicate that is the negation of the unary predicate modified.

## Remarks

If a unary_negate is constructed from a unary predicate Pred(x), then it returns ! Pred(x).

## Example

``````// functional_not1.cpp
// compile with: /EHsc
#include <vector>
#include <functional>
#include <algorithm>
#include <iostream>

using namespace std;

int main()
{
vector<int> v1;
vector<int>::iterator Iter;

int i;
for (i = 0; i <= 7; i++)
{
v1.push_back(5 * i);
}

cout << "The vector v1 = ( ";
for (Iter = v1.begin(); Iter != v1.end(); Iter++)
cout << *Iter << " ";
cout << ")" << endl;

vector<int>::iterator::difference_type result1;
// Count the elements greater than 10
result1 = count_if(v1.begin(), v1.end(), bind2nd(greater<int>(), 10));
cout << "The number of elements in v1 greater than 10 is: "
<< result1 << "." << endl;

vector<int>::iterator::difference_type result2;
// Use the negator to count the elements less than or equal to 10
result2 = count_if(v1.begin(), v1.end(),
not1(bind2nd(greater<int>(), 10)));

cout << "The number of elements in v1 not greater than 10 is: "
<< result2 << "." << endl;
}
``````
```The vector v1 = ( 0 5 10 15 20 25 30 35 )
The number of elements in v1 greater than 10 is: 5.
The number of elements in v1 not greater than 10 is: 3.```

## Requirements

Header: <functional>

Namespace: std

## See Also

Standard Template Library