Question

I’ve defined a C++ class with the following header file:

class EarleyParser
{

    public:

        EarleyParser();
        virtual ~EarleyParser();

        void initialize( string filePath, bool probabilityParse );

    private:

        bool probabilityParser;

        typedef unordered_map< string, list<Production>* > productionHashTable;
        productionHashTable earlyHashTable;

};

As you can see a member element of the class is an unordered_map whose key element is a string and content element is a pointer to a list of objects of another class named Production (don’t mind it, it could be anything).

My question is if I should leave it to the default destructor to free memory allocated, or if I should manually inspect the hash table and delete all of its elements.

In the second case what would be the procedure? Calling this for each element will be ok?

EarleyParser::productionHashTable::const_iterator got = this->earlyHashTable.find( "key" );
delete[] got->second;

Answer 1

You need to clarify who owns the list<Production> objects owned by EarlyParser. If EarlyParser owns them, then you need to free the resources. You can do it by iterating over the list and calling delete on each dereferenced iterator (not delete[]). Or you can store unique_ptr<list<Production>> instead. On the other hand, the simplest solution is to store list<Production> unless you really have very strong reasons for storing pointers.