Question

I am attempting to write my own string class (so I can learn more) and while doing so I noticed I ran into an issue with how the char data is being deleted, when the program closes the destructor of string will be called and there will be a heap error on deleting the data

#include <string.h>

template<typename T>
class String
{
protected:
    T* mData;

public:
    String(const T* data);
    ~String();
};

template<typename T>
String<T>::String(const T* data)
{
    if(data != NULL)
    {
        mData = new T[strlen(data)];
        strcpy(mData, data);
    }
}

template<typename T>
String<T>::~String()
{
    if(mData != NULL)
    {
        delete [] mData;
        mData = 0;
    }
}

int main(void)
{
    String<char> Test("Test");

    return(0);
}

Answer 1

 mData = new T[strlen(data)];
        strcpy(mData, data);

You are allocating one item too few, strcpy copies the nul terminating byte as well as the string