I was porting my Evolutionary Computing homework written in
Python over to D, and I've come across this bug I cannot for the
life of me figure out.
https://gitlab.com/TheGag96/evo-pacman/blob/master/source/pacman/tree.d#L139
I don't think I could cut this down to a smaller reproducible
scenario due to how bizarre and specific this problem is, so I
apologize in advance if this is hard to follow.
Basically, imagine that I have a binary tree class where, due to
how my program is set up, each node will have either children on
both the left and right side or no children at all (the latter
represented by a value of null for Tree's left and right member).
I have a member function called "dup" -- marked const, mind you
-- that just returns a deep copy of the tree and SHOULDN'T make
any changes to the calling object.
I call this function a couple different places and it appears to
function okay, but at the spot I linked, if I call .dup here, it
will corrupt one of the tree's nodes and put something in its
left member for no apparent reason. This oddly doesn't happen on
every Tree calling this function. This could definitely be some
stupid mistake on my part, but the fact that calling a
const-marked function changes the state of the calling object
makes me think something else is afoot here...
I would greatly appreciate anyone who would be willing to take a
look at this. This bug is driving me absolutely nuts.
