Why it is not good code for constructor

[George2]

Hello everyone,


Here is a sample from Dr. Dobb C++. In the analysis, the code is bad below.

But I do not think the code is bad,

1. if bad_alloc is thrown in new int[], we just catch it and write some log;
2. if there are any exception in B's constructor, we will also be in catch block and we could also write some log.

Why it is bad code? Any comments?

(I do not agree that there is resource leak, since if we met with bad_alloc in new int[], there is no memory allocated at all, so no root of memory/resource leak).


http://www.ddj.com/cpp/184401297

C::C(int)
try
   : B(new int[n]) // horrible!
{
   ...
}
catch(Error &e)
{
 
}
 

thanks in advance,
George

[gpraghuram]

If you dont have memory then only you will get a bad_alloc from the compiler.
If you are catching it and if it is being called from another constructor where you have inherited this you have handle the scenario in those places also.

I think that may be one of the reason for telling it a bad code

Raghuram

[George2]

Hi Raghuram,


I agree that there are two situations as you mentioned. But I do not think it is bad code -- will release memory.

Here is my comments. Please feel free to correct me if I am wrong. :-)

1.

If you dont have memory then only you will get a bad_alloc from the compiler.

If there are bad_alloc, means no memory is allocated and no memory leak.

2.

If you are catching it and if it is being called from another constructor where you have inherited this you have handle the scenario in those places also.

I think that may be one of the reason for telling it a bad code

Raghuram

if there are exception (e.g. bad_alloc) in constructor, we just re-throw it until the outer-most constructor (outer-most wrapper), why it is bad code? More descriptions or pseudo code to express your ideas? :-)


regards,
George