Very good idea. The vector don't have to be modified so it'll work.
Thank you for the advice. I make a try an I'll post the result. Philippe Le 05/04/2014 21:59, Rodrigo Rivas a écrit :
On Fri, Apr 4, 2014 at 10:41 PM, Philippe Delrieu <philippe.delr...@free.fr> wrote:Hello, I've some problem to find a solution for something I want to do with a vector of enum. This is an example of what I want to do: trait Base { fn set_something(&mut self); } struct FirstThink; impl Base for FirstThink { fn set_something(&mut self) {} } struct SecondThink; impl Base for SecondThink { fn set_something(&mut self) {} } enum BaseImpl { FirstThinkImpl(~FirstThink), SecondThinkImpl(~SecondThink), } fn some_process(list: &mut Vec<&mut ~Base>) { for think in list.mut_iter() { think.set_something(); } } struct Container { nodeList: Vec<~BaseImpl>, } impl Container { fn add_FirstThink(&mut self, think: ~FirstThink) { self.nodeList.push(~FirstThinkImpl(think)); } fn add_SecondThink(&mut self, think: ~SecondThink) { self.nodeList.push(~SecondThinkImpl(think)); } fn do_some_process(&mut self, fct: fn(&mut Vec<&mut ~Base>)) { I didn't find a simple way to convert the Vec<~BaseImpl> to a &mut Vec<&mut ~Base> to do the call fct(self.nodeList); } } I use the enum pattern to have only one collection of object that impl Base but sometime I have to do specific processing depending if the Base is a FirstThink or SecondThink (not in the example). I use the match as follow match think { FirstThinkImpl(first) => do specific first, SecondThinkImpl(second)=> do specific second, }); Perhaps there is a better way to do. Any suggestions would be appreciated.I think that would be better if the `fct` function take an `std::iter::Iterator<&mut ~Base>` instead of a `Vec`. Naturally, you will not be able to modify the vector, only to iterate through it. But if `fct` is allowed to modify the vector your requirements are impossible in the first place! Then you can write a simple adaptor: impl std::iter::Iterator<&mut ~Base> for Container { // left as an exercise to the reader ;-) }
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