The C++ programming language has constructs that aren't contained by default in UML. Examples are pointers, global functions and variables, references and operator overloading. To enable us to apply these constructs in our models and be capable of taking advantage of it for code generation and C++ notation in UML diagrams, the C++ module uses conventions in the use of the extension features of UML, such as tagged values, stereotypes and data types.

Since UML and C++ are object oriented, there is an obvious correspondence between the UML model elements and C++ structural constructs, e.g, the UML Class is related to the C++ class. These obvious relations will not be described here, since it is assumed that an ArgoUML user that wants to model for C++ has basic knowledge of both C++ and UML.

The C++ module comes with a UML profile for C++, which defines Stereotypes and Tagged Definitions which enable the modeling of C++ specific constructs, such as pointers and references. It also includes Data Types that model the C++ built-in types, such as unsigned long int.

To have these constructs available in our model, we need to configure the UML profile for C++ in the model explicitly via the Project Properties dialog, in the Profiles tab (see Section 10.3.14, “ Project Properties ”).

Tagged values are one of the main means by which we can define code generation behavior. They have a name - the tag - and a value, and are applied to model elements. For each of the possible Tagged values, the C++ profile contains a tag definition, which is contained in a stereotype, applicable to the models elements to which we can define a tagged value's value to specify specific behaviour. So, for instance, to define that the parameter x is a reference, you apply the stereotype cppParameter to it, them you add the tagged value reference with the value true.

The tagged values in use for the C++ module have two categories:

For Boolean tagged values, only the values "true" or " false" are applicable. If a Boolean tagged value does not exist or is invalid for one model element, a default value is assumed by the code generator. In the bellow documentation the default value is marked.

Free format tagged values are only significant if present and if the value isn't an empty String. When the value must follow some sort of format, that is explicitly stated. In this case, there is the chance that the value is invalid. If the value is invalid, no assumptions are made; the generator will trace the problem and ignore the tagged value.

D.1.3.  Parameters

To make the tag definitions applicable to a C++ argument available we apply the cppParameter stereotype to it.

D.1.3.1.  Variable passing semantics

If a Parameter for an Operation is marked as out or inout the variable will be passed by reference (default) or pointer (needs tagged value pointer - see above), otherwise by value.

Return values in UML are simply Parameters marked as return, therefore everything here applies to them, except where explicitly noted.

	Warning
	Note that UML allows multiple return values. This is possible to support in C++ as out parameters, but, currently the generator doesn't supports it. This problem is being handled in issue #3553 - handle multiple return parameters.

D.1.3.2.  Parameter tagged values

pointer

true || false (default) - same as for Attributes.

reference

ditto

  function Testclass::Testclass()
  // section -64--88-0-40-76f2e8:ec37965ae0:-7fff begin
 {
 }
  // section -64--88-0-40-76f2e8:ec37965ae0:-7fff end
      

  void newOperation(std::string test = "fddsaffa")
  // section 603522:ec4c7ff768:-7ffc begin
 {
 }
  // section 603522:ec4c7ff768:-7ffc end