CODEWITHSUNDEEP
c++
kasis
kasis

Reputation: 35

is it legal to throw internal object exception from function

It's illegal to throw an exception from a function like this?
In Eclipse it work...
So it's true? and we can throw internal object in throwing exceptions?

class Bad {
    int i;
public:
    void what() { cout << "exp" << i; }
};

class A {
public:
    void f() {
        Bad e;
        throw e;
    } // e are deleted by d'tor?
};

int main() {
    A a;
    try {
        a.f();
    } catch (Bad& e) // What happen here? we catch reference to some object that
                     // was deleted by Bad dt'or
    {
        cout << "in catch";
        e.what(); // what happen here?
    }
    return 0;
}

Upvotes: 1

Views: 126

Answers (1)

Mike Seymour
Mike Seymour

Reputation: 254631

Your code is fine. throw e; makes a copy of e, which is destroyed after the exception has been handled. The handler is given a reference to that copy.

You could get in trouble if you threw a pointer to the local variable; the variable would be destroyed before handling the exception, leaving the pointer invalid. But throwing a pointer would be rather an odd thing to do in any case.

Upvotes: 3

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