UML25 — The current criteria used in UML for BehavioralFeature::isDistinguishable() is insufficient in practice

The current criteria only looks at the ordered collection of owned parameter types as a key for distinguishing behavioral features.
For example, it means that, for UML, the following pairs of operations of the same name are not distinguishable:

// difference in the parameter direction
op1(String)
op1():String

// difference in the parameter effect
op2(update String)
op2(delete String)

// difference in the parameter exception
op3(Throwable)
op3() throws Throwable

// difference in the parameter collection characteristics
op4(Set(String))
op4(String[1])

This means that UML is not able to represent some well-known programming languages where the above characteristics contribute to the signature of distinguishable operations (e.g., C, C++, Java, C#, …)

This can be easily fixed.

In the OCL for BehavioralFeature::isDistinguishableFrom(), replace:

...>isUnique(ownedParameter>collect(type))

With:

…>isUnique(ownedParameter>collect(p|Tuple

))

Since BehavioralFeature::ownedParameter is an ordered collection, the current definition constructs an ordered collection of the owned parameter types as a key for distinguishing BehavioralFeatures.

agreed