> no question about aliasing or whether other code is referencing the value Well, actually, there's quite a bit of convention here. The 'could cause undefined

> no question about aliasing or whether other code is referencing the value Well, actually, there's quite a bit of convention here. The 'could cause undefined behavior' code I hashed out as an example uses a const reference, which is the widely accepted best practices for copy semantics. There's sort of an implied 'and the concrete implementation will copy this value if it needs it for longer than the duration of the method call', but that's a convention; it's not enforced by compiler. We could pass these sorts of parameters by value, but there are reasons people like to avoid passing by value as a default. Engineers could define interfaces with only pass-by-value arguments, but there