Help with semi-complex C++ assignment
c++
Solution
The way `std::map` works is that it will allocate a node you are trying to reference if it does not exist yet. That means unless you are allocating your submap(s) and inserting them into your supermap(s), you're going to be given pointers to memory you don't own. At that point when you try to write to that memory you will crash.
Do the maps need to be heap allocated? If not you can change the type to:
map<int, map<int, map<int, CString> > > batch; // don't forget the spaces
and your call can be:
batch[atoi(transnum)][1][atoi(*docnum)] = page;
Problem
This is a really easy question I'm sure but I'd appreciate the help. :) Here's my variable in the .h file: ``` map<int, map<int, map<int, CString>*>*> batch; ``` Here's me trying to assign a value: ``` ((*((*(batch[atoi(transnum)]))[1]))[atoi(*docnum)]) = page; ``` I added some extra parentheses while trying to figure this out in order to make sure the derefs were being processed in the right order - unfortunately, it still doesn't work. My application just crashes when running this line. I have it wrapped in a try {} catch {}, but no exception appears to be thrown. I don't use C++ very often and am wondering whether someone can tell me what I'm doing incorrectly. Here's the relationship I'm trying to model: List of transaction numbers (integers), needs to be ordered by key. For each transaction number, I have two types of documents, Payments and Invoices (buckets represented by 0 and then 1 respectively in my data struct above) In each type bucket, there can be one or more documents, These documents need to be ordered by id (docid) Each docid links to a string that consists of a comma-delimited list of files on the file system for processing. If you think there's a better data structure to use, I'd be interested to hear it. EDIT: I know there are many better ways to do this. The scenario was that I was handed a heap of horrible MFC-riddled C++ code and told to have something done yesterday. It basically boiled down to getting the data structure in there, loading it up and then outputting it somewhere else. I was just trying to pound it out quickly when I asked this question. I appreciate the design suggestions though.