What if one of control paths doesn't return a value?

Asked Apr 08 '20 at 16:57

Active Apr 08 '20 at 17:05

Viewed 32 times

int f(int n)
{
    if (n > 0) return 1;
}

int main()
{
    f(0); // Does the C++ standard see this as an error?
}

Another example:

int f()
{
    try
    { 
        return mayThrow();
    }  
    catch(...)
    {
        throw; // rethrow and no return. Is this conforming to the C++ standard?
    }
}

int main()
{
    f();
}

Third example:

int f()
{
    try
    { 
        throw 0;
    }  
    catch(...)
    {
        throw; // rethrow and no return. Is this conforming to the C++ standard?
    }
}

int main()
{
    f();
}

edited Apr 08 '20 at 17:05

asked Apr 08 '20 at 16:57

xmllmx

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2

undefined behavior, and at compile time a warning or an error depending on the compiler and options :-) – bruno Apr 08 '20 at 16:59
I believe the first example is an Undefined Behavior the second is not. – drescherjm Apr 08 '20 at 17:00
1

@drescherjm Depends on whether or not `mayThrow()` does actually throw. – walnut Apr 08 '20 at 17:01
@walnut, what if `mayThrow()` does throw? – xmllmx Apr 08 '20 at 17:04
@xmllmx Then you are not flowing of the end of the function and everything is fine, see the answers in the linked duplicates. – walnut Apr 08 '20 at 17:05

What if one of control paths doesn't return a value?

0 Answers0