ReadablePropertyMap

ReadablePropertyMap

A ReadablePropertyMap provides read-access to the value object associted with a given key via a call to the get() function. The get() function returns a copy of the value object.

Refinement of

CopyConstructible

Notation

`PMap`	A type that is a model of LvaluePropertyMap.
`pmap`	An object of type `PMap`.
`key`	An object of type `boost::property_traits<PMap>::key_type`.

Associated Types

Value Type	`boost::property_traits<PMap>::value_type`	The type of the property.
Key Type	`boost::property_traits<PMap>::key_type`	The type of the key object used to look up the property. The property map may be templated on the key type, in which case this typedef can be `void`.
Property Map Category	`boost::property_traits<PMap>::category`	The category of the property: a type convertible to `readable_property_map_tag`.

Valid Expressions

Name	Expression	Return Type	Description
Get Property Value	`get(pmap, key)`	`value_type`	Lookup the property of the object identified by `key`.

Design Notes

At various times the name "read-only" was considered for this concept. However, that name is inappropriate because concepts are inherently positive, not negative. This becomes obvious when we define the ReadWritePropertyMap, which refines both the ReadablePropertyMap and the WritablePropertyMap concept. It would not make much sense to combine "read-only" and "write-only" concepts!

Jeremy Siek, Univ.of Notre Dame (jsiek@lsc.nd.edu)