On Mon, 8 Nov 2010 18:13:54 +1000 "Daniel Murphy" <[email protected]> wrote:
> "spir" <[email protected]> wrote in message > news:[email protected]... > I'd like to know, aside user-side semantics, whether the compiler uses the > "in" qualifier for efficiency (pass arrays & structs by ref under the > hood?). Well, seems obvious, but there may be some hidden constraint I'm > unable to realise. > > The spec states: "The in storage class is equivalent to const scope." > > So, no, the compiler never implicitly uses ref to pass in parameters. > > It could be possible with a rule like "pass by const ref if param.sizeof > x > bytes", but I think this would require an abi change. Then, if I pass a huge array/string or struct as "in", it is copied, right? Is the only way to avoid copy then to pass as ref? I take the opportunity to ask about dynamic arrays. There is an internally pointed element-array, but is the array's interface (the kind of struct holding ptr & length) itself implicitely referenced? Denis -- -- -- -- -- -- -- vit esse estrany ☣ spir.wikidot.com
