Binary Heap Errors Class level vs function level

[Chris Pons]

I'm still messing around with binary heaps. I've successfully 
created and used it on the function level but for some reason 
when I move it to the class level I get an error. Furthermore, 
i'm not entirely sure how to use a binary heap without auto as 
the type.

class AStar
{
ReferenceNode[] openListContainer;
auto openList = BinaryHeap!(ReferenceNode[], "a.fScore > 
b.fScore")(openListContainer, 0 ); // Error
}


Error	1	Error: template instance 
BinaryHeap!(ReferenceNode[],"a.fScore > b.fScore") 
BinaryHeap!(ReferenceNode[],"a.fScore > b.fScore") does not match 
template declaration BinaryHeap(Store,alias less = "a < b") if 
(isRandomAccessRange!(Store) || 
isRandomAccessRange!(typeof(Store.init[])))	C:\Users\CP\Documents\Visual 
Studio 2010\Projects\D\STDS\NPC.d	101	


However this is ok:

class AStar
{
void RandomFunction()
{
ReferenceNode[] openListContainer;
openListContainer.length = 500;
auto openList = BinaryHeap!(ReferenceNode[], "a.fScore > 
b.fScore")(openListContainer, 0 ); //This is ok
}
}

I'd also like to try this, but can't seem to figure it out:

class AStar
{
ReferenceNode[] openListContainer;
auto openList; //no identifier for declarator openlist

this()
{
openListContainer.length = 500;
openList = = BinaryHeap!(ReferenceNode[], "a.fScore > 
b.fScore")(openListContainer, 0 );
}
}

If I know what type openList was, after creating the heap, I 
could simply use that. I tried using typeid( openList ) to find 
out. I got the type being something like:

BinaryHeap!(Referencenode[], "a.fScore > b.fScore") openList;

However trying to use this as the type gives me this error:


Error	1	Error: template instance 
BinaryHeap!(ReferenceNode[],"a.fScore > b.fScore") 
BinaryHeap!(ReferenceNode[],"a.fScore > b.fScore") does not match 
template declaration BinaryHeap(Store,alias less = "a < b") if 
(isRandomAccessRange!(Store) || 
isRandomAccessRange!(typeof(Store.init[])))	C:\Users\CP\Documents\Visual 
Studio 2010\Projects\D\STDS\NPC.d	101	


Error	2	Error: BinaryHeap!(ReferenceNode[],"a.fScore > b.fScore") 
is used as a type	C:\Users\CP\Documents\Visual Studio 
2010\Projects\D\STDS\NPC.d	101	

I'm just trying to get a variable called openList to the class 
level so it doesn't keep getting initialized everytime the 
function is called.

Any ideas on how to work this out?