Memory leak in class Constructor of c++

Question

I have the following class

class CSample
{
   char* m_pChar;
   double* m_pDouble;

 CSample():m_pChar(new char[1000]), m_pDouble(new Double[1000000])
{
}
~CSample()
{
   if(m_pChar != NULL) delete [] m_pchar;
   if(m_pDouble != NULL) delete [] m_pDouble;
}
};

and in my main() function i'm trying to create object of CSample

int main()
{
    try
  {
    CSample objSample;
  }

catch(std::bad_alloc)
{
  cout<<"Exception is caught !!! Failed to create object";
}

}

Say while allocating the memory for m_pDouble in constructor's initializer list, it throws the exception because of insufficient available memory. But for m_pChar it is already allocated. Since object itself is not created, the destructor wouldnt be called. Then there will be memory leak for m_pChar.

How do you avoid this memory leak ?

Answer 1

You can easily avoid this kind of problem by using a vector instead.

class CSample
{
   std::vector<char> m_pChar;
   std::vector<double> m_pDouble;

   CSample():m_pChar(1000), m_pDouble(1000000)
   {
   }
};

Generally speaking, you should aim to write classes that do not require a destructor. This makes them trivially obey the Rule of Three.