Class template last_value<optional<T>>

Class template last_value<optional<T>>

boost::last_value<optional<T>> — Evaluate an InputIterator sequence.

Synopsis

template<typename T> 
class last_value<optional<T>> {
public:
  // types
  typedef optional<T> result_type;

  // invocation
  template<typename InputIterator> 
    result_type operator()(InputIterator, InputIterator) const;
};

Description

`last_value` invocation

template<typename InputIterator> 
  result_type operator()(InputIterator first, InputIterator last) const;

Effects:	Attempts to dereference every iterator in the sequence `[first, last)`. Swallows boost::expired_slot exceptions thrown by failed dereference attempts.
Returns:	An `optional<T>` containing the result of the last successful iterator dereference, or an uninitalized `optional<T>` if no iterators were successfully dereferenced.