Class diagram - how to describe the data type of a graph?
How to represent the data type of a graph in a class diagram
Class diagram: http://www.uml-diagrams.org/class-diagrams.html
Do I have to specify how the graph datatype is implemented? Or is there a symbol for the graph?
UML diagrams automatically switches graphics ( diagrams state machines , activity diagrams ), but will not provide what you expect.
UML was originally intended for object-oriented programming, not programming in general. This will allow you to represent object-oriented functions rather than general programming functions (since graphs are not object-oriented functions).
This way, you will be able to represent the Graph class as a class and not as a graph data type. Graph is abstract data types, it depends on the programmer (it will be strongly related to how you program, you can manipulate graphs without OOP).