new and memory allocation error

[MisterEd]

Another quick question!

When standard new cannot allocate the requested storage in C++ which of the following does it do? (standard behaviour). (can be more than one answer)

1 - throws a bad_alloc exception
2 - throws an insufficient_memory exception
3 - returns null
4 - returns silently with no effect on the expression
5 - logs an error message to the mem_err.log file


I would have said definitly 1, any other thoughts or interesting info about the others?

Is there any way I can force this error so I can try it out?

[Lindley]

If the nothrow version of new is used, then 3 would be correct. However, the question probably isn't asking about that.

[MisterEd]

thanks for the reply, so would you think it is just 1?

[Lindley]

Well, there would be no point in throwing two exceptions for the same thing, and if an exception is thrown then it doesn't make sense to talk about a return value. Plus I can't imagine standard C++ doing any logging you didn't ask it to do.

I suppose #4 might make sense depending on what they mean by "returns silently". Jumping directly to the catch block (if any) will certainly not have any effect on the expression...