std::for_each
From Cppreference
| Defined in header
<algorithm> | ||
| template< class InputIterator, class UnaryFunction >
UnaryFunction for_each( InputIterator first, InputIterator last, UnaryFunction f ); | ||
Applies the given function f to each of the elements in the range [first, last).
Contents |
Parameters
| first, last | - | the range to apply the function to |
| f | - | the function to be applied |
Return value
function that was applied
Complexity
linear in the distance between first and last
Equivalent function
template<class InputIterator, class UnaryFunction> UnaryFunction for_each(InputIterator first, InputIterator last, UnaryFunction f) { for (; first != last; ++first) { f(*first); } return f; }
Example
The following code snippets define a unary function then use it to increment all of the elements of an array:
template<class T> struct increment : public unary_function<T, void> { void operator()(T& x) { x++; } }; ... int nums[] = {3, 4, 2, 9, 15, 267}; const int N = 6; cout << "Before, nums[] is: "; for (int i = 0; i < N; i++) { std::cout << nums[i] << " "; } std::cout << std::endl; std::for_each(nums, nums + N, increment<int>()); std::cout << "After, nums[] is: "; for (int i = 0; i < N; i++) { std::cout << nums[i] << " "; }
Output:
Before, nums[] is: 3 4 2 9 15 267 After, nums[] is: 4 5 3 10 16 268
See also
| applies a function to a range of elements (function template) | |
