what does I mean in c++?

Question

I have a method, where x is a class and in the UML , for a different class (that uses class x ), a method is written as:

+setX(x I &)    

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What does the I in the argument mean? or is it just a typo?

Answer 1

It looks like a poorly formatted UML entry regarding a public function named setX taking a reference to an instance of x , and naming that reference I .

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I'm guessing the author meant to write +setX(INOUT I : x) but got the syntax of the implementation language (in this case c++ ) mixed up with the Unified Modeling Language .

INOUT I : x will make setX accept a variable used for both input and output of type x , and name this parameter I .

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^{Note: setX(x I&) is not legal c++ , but setX(x& I) is.}