Type polymorphism and type variance

[Ali Çehreli]

On 12/05/2012 09:51 AM, js.mdnq wrote:

 > (if your having trouble understanding the problem then just think of how
 > you would efficiently store the nodes and edges of a directed acyclic
 > graph. Each node is of a somewhat arbitrary type and edges are functions
 > over the nodes that do computations, possibly changing the nodes
 > "value". These all need to be stored someway so that a full computation
 > chain can be carried out(the graph structure is arbitrary).)

I do not fully understand the issue yet but I smell "double dispatch" in 
there. There is no elegant solution of double dispatch at least in C++ 
but there are a number of solutions with certain compromises. I will 
read your post more carefully later.

Ali