I cannot think why you would want to a shared pointer argument instead of a reference. A better interface would be: void foo( const Widget& widget ); Calle

I cannot think why you would want to a shared pointer argument instead of a reference. A better interface would be: void foo( const Widget& widget ); Called by foo( *widget_ptr ); or foo( widget ); No doubt there are special circumstance by normally foo would not care, should not care, whether the Widget is on the stack or heap, controlled by a dump or smart pointer.