Script execution order

[Damadger]

Well I am kind of confused with the execution order in the following script, I want to know if the delete function is executed within each condition or sometimes it is skipped :

void Students::addSubject(std::istream& in)
{
        Custom* sys = new Custom;
        std::string last;
        in>>last;


        if (last == "x" )
        {
                if(Hw.empty())
                {
                        std::cout<< "\n>>"<<"You must at least enter 1 homework subject."<< std::endl;
                        std::cout << "\nEnter subject: ";
                        in.clear();
                        addSubject(in);
                }
                else
                {
                        std::cout<< ">>"<<" Subjects data completed."<< std::endl;
                }
        }
        else if(last != "x")
        {
                std::string editedSubj = sys->toLower(last);
                if(Hw.find(editedSubj) != Hw.end())
                        std::cout<< "\n>>"<<last << " is a duplicated subject."<< std::endl;
                else
                {
                        Hw[editedSubj] = (double)-1;
                        std::cout<< "\n>>"<<last << " subject was added to homework list.\n"<< std::endl;
                        std::cout<< std::string(80,'-')<<std::endl;
                }
                std::cout << "\nEnter subject ( 'x' to finish) : ";
                in.clear();
                addSubject(in);

        }

        delete sys;


}

[ne555]

Custom sys; Now you don't have to worry.

The delete will not be executed if an exception is thrown.

[Damadger]

I know i can use that :p , but i want to know just in case. So In the above the delete will be executed within all condition, what if there is a return statement in one of the conditions. like that?

void function()
{
    Class* thing = new Class;
    if{
        ...
        return;
    }
    else{
        ....
        return;
    }
    delete thing ;
}

[firedraco]

Then you have to put a delete in front of the return. However, even if you do that, you are still screwed if someone throws an exception.