Class optional_last_value<void>

Boost C++ Libraries

Class optional_last_value<void>

boost::signals2::optional_last_value<void> — Evaluate an InputIterator sequence.

Synopsis

// In header: <boost/signals2/optional_last_value.hpp>


class optional_last_value<void> {
public:
  // types
  typedef void result_type;

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

Description

This specialization of signals2::optional_last_value is provided to cope with the fact that there is no such thing as an optional<void>, which optional_last_value would otherwise try to use as its result_type. This specialization instead sets the result_type to be void.

`optional_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).