Can the C++ `new` operator ever throw an exception in real life?

Question

Can the new operator throw an exception in real life?

And if so, do I have any options for handling such an exception apart from killing my application?

Update:

Do any real-world, new-heavy applications check for failure and recover when there is no memory?

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See also:

• How often do you check for an exception in a C++ new instruction?
• Is it useful to test the return of “new” in C++?
• Will new return NULL in any case?

Answer 1

Yes, new can and will throw if allocation fails. This can happen if you run out of memory or you try to allocate a block of memory too large.

You can catch the std::bad_alloc exception and handle it appropriately. Sometimes this makes sense, other times (read: most of the time) it doesn't. If, for example, you were trying to allocate a huge buffer but could work with less space, you could try allocating successively smaller blocks.

Answer 2

The new operator, and new[] operator should throw std::bad_alloc, but this is not always the case as the behavior can be sometimes overridden.

One can use std::set_new_handler and suddenly something entirely different can happen than throwing std::bad_alloc. Although the standard requires that the user either make memory available, abort, or throw std::bad_alloc. But of course this may not be the case.

Disclaimer: I am not suggesting to do this.