Container insertion and removal

[Michel Fortin]

On 2010-03-08 13:01:32 -0500, Andrei Alexandrescu 
<SeeWebsiteForEmail at erdani.org> said:

> softXxx functions that remove data should guarantee that existing 
> ranges not including the removed elements will continue to operate on 
> the range without seeing the removed elements. There is no guarantee 
> that soft removal offers for ranges spanning the removed elements. (I'm 
> unclear on this last topic.)

That won't work for a vector as ranges that are further then the 
removed element need adjustment too.

Just an idea, perhaps remove and other mutator functions for the 
container could take a list of range to update at the same time they do 
the operation. This way you don't even need a soft function, if remove 
can't accept other ranges then it won't take other ranges as an 
argument. For instance:

	class Container {
		void remove(Range toRemove, Range[] needAdjustment);
	}

	Container x = new Conatiner();
	auto a = x[];
	auto b = x[4..6];
	auto c = x[2..4];
	x.remove(c, [a, b]); // remove elements from c, adjust ranges a and b.

	OtherContainer y = new OtherContainer();
	auto d = y[];
	auto e = y[2..4];
	y.remove(e, [d]); // error, container is unable to adjust other ranges.


-- 
Michel Fortin
michel.fortin at michelf.com
http://michelf.com/