28 Algorithms library [algorithms]

28.5 Non-modifying sequence operations [alg.nonmodifying]

28.5.4 For each [alg.foreach]

template<class InputIterator, class Function> Function for_each(InputIterator first, InputIterator last, Function f);
Requires: Function shall meet the requirements of MoveConstructible (Table 23).
[ Note
:
Function need not meet the requirements of CopyConstructible (Table 24).
— end note
 ]
Effects: Applies f to the result of dereferencing every iterator in the range [first, last), starting from first and proceeding to last - 1.
[ Note
:
If the type of first satisfies the requirements of a mutable iterator, f may apply non-constant functions through the dereferenced iterator.
— end note
 ]
Returns: f.
Complexity: Applies f exactly last - first times.
Remarks: If f returns a result, the result is ignored.
template<class ExecutionPolicy, class ForwardIterator, class Function> void for_each(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last, Function f);
Requires: Function shall meet the requirements of CopyConstructible.
Effects: Applies f to the result of dereferencing every iterator in the range [first, last).
[ Note
:
If the type of first satisfies the requirements of a mutable iterator, f may apply non-constant functions through the dereferenced iterator.
— end note
 ]
Complexity: Applies f exactly last - first times.
Remarks: If f returns a result, the result is ignored.
Implementations do not have the freedom granted under [algorithms.parallel.exec] to make arbitrary copies of elements from the input sequence.
[ Note
:
Does not return a copy of its Function parameter, since parallelization may not permit efficient state accumulation.
— end note
 ]
template<class InputIterator, class Size, class Function> InputIterator for_each_n(InputIterator first, Size n, Function f);
Requires: Function shall meet the requirements of MoveConstructible
[ Note
:
Function need not meet the requirements of CopyConstructible.
— end note
 ]
Requires: n >= 0.
Effects: Applies f to the result of dereferencing every iterator in the range [first, first + n) in order.
[ Note
:
If the type of first satisfies the requirements of a mutable iterator, f may apply non-constant functions through the dereferenced iterator.
— end note
 ]
Returns: first + n.
Remarks: If f returns a result, the result is ignored.
template<class ExecutionPolicy, class ForwardIterator, class Size, class Function> ForwardIterator for_each_n(ExecutionPolicy&& exec, ForwardIterator first, Size n, Function f);
Requires: Function shall meet the requirements of CopyConstructible.
Requires: n >= 0.
Effects: Applies f to the result of dereferencing every iterator in the range [first, first + n).
[ Note
:
If the type of first satisfies the requirements of a mutable iterator, f may apply non-constant functions through the dereferenced iterator.
— end note
 ]
Returns: first + n.
Remarks: If f returns a result, the result is ignored.
Implementations do not have the freedom granted under [algorithms.parallel.exec] to make arbitrary copies of elements from the input sequence.