Need an advice with pointer

sitesv

Hi! I typed a short simple code... Is there a good way to avoid memory leak in case of 'return'?
I don't want to 'delete mstr' in each 'return' statement.

void my_func(){
         my_struct *mstr = new my_struct;
         if(!check1()) return;
         mstr->val1 = val1;
         if(!check2()) return;
         mstr->val2 = val2;
         my_vector.push_bach(mstr);
}

KroMignon

@sitesv said in Need an advice with pointer:

I don't want to 'delete mstr' in each 'return' statement.

use smart pointers:

SGaist

Hi,

Or do both checks before and return early since if any of the two fails you do not add anything to your vector.

sitesv

@KroMignon said in Need an advice with pointer:

use smart pointers:

But how to be if pointer was added to the vector? (in case of smart pointers)

KroMignon

@sitesv said in Need an advice with pointer:

But how to be if pointer was added to the vector? (in case of smart pointers)

You could use std::unique_ptr<>() or Qt equivalent QScopedPointer<>():

void my_func(){
         auto mstr = std::unique_ptr<my_struct>(new my_struct);
         //auto mstr = QScopedPointer<my_struct>(new my_struct);
         if(!check1()) return;
         mstr->val1 = val1;
         if(!check2()) return;
         mstr->val2 = val2;
         // convert smart pointer back to raw pointer
         my_vector.push_back(mstr.release());
         //=> for QScopedPointer my_vector.push_back(mstr.take());
}

sitesv

@KroMignon
Big thanks to you!

SGaist

A version without useless memory allocation:

void my_func()
{
    if (!check1() || !check2()) {
        return;
    }
    my_struct *mstr = new my_struct;
    mstr->val1 = val1;
    mstr->val2 = val2;
    my_vector.push_back(mstr);
}

It can even be shorter if my_struct has a constructor.