{ return hppbard{}; }

In some languages there is such a thing as tuple which makes real to write such code (this time it's in python): def f(x):  #   do stuff return (True, modified_string) success, modified_string = f(something)  C++ hadn't such feature until C++11. That was one of the reasons to pass variable as referenced argument, which ended up creating huge code bases that have unused arguments in it's functions. That happened in order to save revers compatibility and allow clients to use stable interfaces to access libraries without checking the version of dynamically attached library in order to use correct functions.

For a long time in C++ was no fast way to deal with return value. They were copied and there was no hope to change it. Some have used return parameters in argument list like: void GetObjectsInArea(Area exactArea, ObjectList& objList); To avoid unnecessary copies and speed up the execution developers were doing a lot of work. Eventually when optimized code were becoming unreadable the developers would abandon it and the code would transform into legacy code at some point.

Defining a function you might want to make some of it's arguments to be constant to avoid unnecessary copying or have a bit more strict interface. There is another way to use constness - there we meet constant class members.