Luna::copy_if

template <typename _InputIt, typename _OutputIt, typename UnaryPredicate>
_OutputIt copy_if(_InputIt first, _InputIt last, _OutputIt d_first, UnaryPredicate pred)

Copies elements that pass user-defined function from one range to another range. The relative order of elements that are copied is preserved.

Parameters

• in first

  The iterator to the first element of the source range.

• in last

  The iterator to the one-past-last element of the source range.

• in d_first

  The iterator to the first element of the destination range.

• in pred

  The user-defined unary predicate which returns ​true for elements that should be copied.

Return value

Returns one iterator to the one-past-last element of the destination range.

Valid Usage

• The expression pred(v) must be convertible to bool for every argument v of type VT, where VT is the value type of _InputIt, and must not modify v.