删除动态分配的对数组，引发无效地址错误

Question

I have a very curious problem. I have a custom class Set , and a custom class Map (I have to recreate the standard library implementations for a class). In my map class, I create an array of pair<string, Set<string>> . But, when I expand my array of values and re-hash the values, I want to delete my old array. But, Whenever (and wherever in my code...) I try to, I get a Invalid address specified to RtlValidateHeap error. This happens even when the delete call is on the line after my new[] statement.

I have private class variable I call pair<string, Set<string>> *values; . Then in my constructor I do the following.

values = new pair<string, Set<string>>[tableSize];

Then when I got to delete values in a member function it threw the invalid address error. The code is below - I swap newValues , and values , then delete newValues in the reallocate() function. That is where the error is thrown

Node: the map is functioning perfectly. I can hash, store, and recall values without any errors.

Expanded Code:

template<>
class Map<std::string, Set<string>> : public MapInterface<string,Set<string>>{
public:

Map() {
    numItems = 0;
    tableSize = BonusHashTableSize;
    values = new pair<string, Set<string>>[tableSize];
    for (int i = 0; i < tableSize; ++i) {
        values[i].first = "";
    }
};

~Map() {
    for (int i = 0; i < tableSize; ++i) {
        if (values[i].first != "") {
            values[i].second.clear();
        }
    }
    delete[] values;
};


void reallocate() {
    tableSize *= 2;
    pair<string, Set<string>> *newValues = new pair<string, Set<string>>[tableSize];
    for (int i = 0; i < tableSize; ++i) {
        newValues[i].first = "";
        newValues[i].second = Set<string>();
    }
    for (int i = 0; i < tableSize / 2; ++i) {
        if (values[i].first != "") {
            int newIndex = rehash(newValues, values[i].first);
            newValues[newIndex].first = values[i].first;
            newValues[newIndex].second = values[i].second;
            Set<string> test = newValues[newIndex].second;
        }
    }
    std::swap(values, newValues);
    delete[] newValues;

//member functions

private:
pair<string, Set<string>> *values;
int tableSize;
int numItems;
};

Answer 1

Remove delete values from constructor. What is the purpose of allocation if you are just going to delete in the next line? And also you are using the deleted memory in the next for loop block.

Since you have deleted it here , it will cause invalid memory access error anywhere else because you are trying to delete already deleted memory location.