[trendia]

Maybe I'm mistaken... but at least in C++ the implementation of Foo::Bar() is similar to Bar(Foo):

    Bar(Foo * foo); // how Foo::Bar() is implemented

So while Bar(Foo) could be passed as several ways:

    Bar(Foo foo);
    Bar(Foo &foo);
    Bar(Foo *foo);
    ....

there isn't really a huge distinction between the two except for syntax and locality within the source file. (That is, class methods are all defined in the class and can't be spread across multiple header files).