A RetroSearch Logo

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Search Query:

Showing content from https://cplusplus.com/reference/algorithm/none_of/ below:

function template

<algorithm>

std::none_of 
template <class InputIterator, class UnaryPredicate>  bool none_of (InputIterator first, InputIterator last, UnaryPredicate pred);

Test if no elements fulfill condition

Returns true if pred returns false for all the elements in the range [first,last) or if the range is empty, and false otherwise.

The behavior of this function template is equivalent to:


1
2
3
4
5
6
7
8
9
template<class InputIterator, class UnaryPredicate>
  bool none_of (InputIterator first, InputIterator last, UnaryPredicate pred)
{
  while (first!=last) {
    if (pred(*first)) return false;
    ++first;
  }
  return true;
}

Parameters
first, last
Input iterators to the initial and final positions in a sequence. The range used is [first,last), which contains all the elements between first and last, including the element pointed by first but not the element pointed by last.
pred
Unary function that accepts an element in the range as argument and returns a value convertible to bool. The value returned indicates whether the element fulfills the condition checked by this function.
The function shall not modify its argument.
This can either be a function pointer or a function object.

Return valuetrue if pred returns false for all the elements in the range [first,last) or if the range is empty, and false otherwise.

Example 
1
2
3
4
5
6
7
8
9
10
11
12
13
// none_of example
#include <iostream>     // std::cout
#include <algorithm>    // std::none_of
#include <array>        // std::array

int main () {
  std::array<int,8> foo = {1,2,4,8,16,32,64,128};

  if ( std::none_of(foo.begin(), foo.end(), [](int i){return i<0;}) )
    std::cout << "There are no negative elements in the range.\n";

  return 0;
}

Output: 
There are no negative elements in the range.


Complexity Up to linear in the distance between first and last: Calls pred for each element until a match is found.

Data races Some (or all) of the objects in the range [first,last) are accessed (once at most).

Exceptions Throws if either pred or an operation on an iterator throws.
Note that invalid parameters cause undefined behavior.

See also
all_of
Test condition on all elements in range (function template)
any_of
Test if any element in range fulfills condition (function template)
find_if_not
Find element in range (negative condition) (function template)

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4