Identity Property Map

##

    boost::typed_identity_property_map<T>

    typedef boost::typed_identity_propoperty_map<std::size_t> boost::identity_property_map

The `typed_identity_property_map` property map applies the identity function, that is, it just returns a copy of the key object that was input. The key and value types are both the same as the template parameter `T`. The `identity_property_map` name is for the common case where the key and value type are `std::size_t` (this name is deprecated for use within Boost.Graph).

Note: Previously the function `get()` and `operator[]` for `identity_property_map` were overloaded to return a copy of keys of any type, i.e., not just `size_t`. These overloads are now deprecated, because they did not adhere to the property map concepts.

### Where Defined

`boost/property_map/property_map.hpp`

### Model of

Readable Property Map

### Template Parameters

Parameter | Description | Default
--- | --- | ---
`T` | Must be Copy Contructible |

### Associated Types

Type | Description
--- | ---
`boost::property_traits<typed_identity_property_map<T> >::value_type` | This type is `T`.
`boost::property_traits<typed_identity_property_map<T> >::key_type` | This type is `T`.
`boost::property_traits<typed_identity_property_map<T> >::reference` | This type is `T`..
`boost::property_traits<typed_identity_property_map<T> >::category` | This type is `boost::readable_property_map_tag`.

### Member Functions

Member | Description
--- | ---
`typed_identity_property_map()` | Default constructor.
`typed_identity_property_map(const typed_identity_property_map<T>& x)` | Copy constructor.
`T operator[](const T& x) const` | Returns a copy of object `x`.

### Non-Member Functions

Member | Description
--- | ---
`T get(const typed_identity_property_map<T>& pmap, const T& x)` | Returns a copy of object `x`.

Copyright © 2000-2012 | Jeremy Siek, Univ.of Notre Dame (jsiek@lsc.nd.edu) Lie-Quan Lee, Univ. of Notre Dame (llee1@lsc.nd.edu) Andrew Lumsdaine, Univ.of Notre Dame (lums@lsc.nd.edu) Alex Hagen-Zanker