Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for an old version of boost. Click here for the latest Boost documentation.

Struct template iterator

boost::type_erasure::iterator

Synopsis

// In header: <boost/type_erasure/iterator.hpp>

template<typename Traversal, typename T = _self, 
         typename Reference = boost::use_default, 
         typename DifferenceType = std::ptrdiff_t> 
struct iterator {
  // types
  typedef unspecified    value_type;     
  typedef Reference      reference;      
  typedef DifferenceType difference_type;
};

Description

The iterator concept can be used for any iterator category.

The value_type of the iterator is deduced. To force it to be a specific type, use the same_type concept.

Example:

mpl::vector<
  iterator<boost::forward_traversal_tag>,
  same_type<iterator<boost::forward_traversal_tag>::value_type, int> > int_it;

Template Parameters

```
typename Traversal
```
must be one of boost::incrementable_traversal_tag, boost::single_pass_traversal_tag, boost::forward_traversal_tag, boost::bidirectional_traversal_tag, and boost::random_access_traversal_tag.
```
typename T = _self
```
The placeholder representing the iterator.
```
typename Reference = boost::use_default
```
The reference type. If it is boost::use_default, then reference will be value_type&.

typename DifferenceType = std::ptrdiff_t

The iterator's difference type.