Memory Management

[geek4u]

how will u know if memory is available before using new operator? any mechanism

[Bazzy]

You can't but you can catch an exception in case new fails

[EzwRko23]

You should not rely on the exception, either. Many systems won't throw it.
I can allocate easily 2 Gigs of memory on a system having just 256 MB of physical memory installed, and no exception is thrown on Linux. The app will get killed, when it tries to use all those memory.

[jsmith]

xorebxebx: set your overcommit_memory flag to 0 to fix that.

But yes, in general, most apps handle out-of-memory conditions by unexpectedly crashing, as there is
little else that can be done.

[Kyon]

Include the <new> library and add the (nothrow) parameter. Then check if the outputted pointer is NULL. If it is, the new-call failed.

[filipe]

Kyon wrote:

Include the <new> library

It's a standard header, not a library.

[Kyon]

Either way, include it if you want the (nothrow) parameter to be usable.

[D80DSL3A]

You mean this method can't be relied on?

int* pInt = NULL;
pInt = new int[50];// for example
if( pInt == NULL)
    return( err );

I'm in trouble then!

[jsmith]

No, because if new fails on line 2, it will throw std::bad_alloc; it will not return NULL.

Go off now and fix all your code.

[D80DSL3A]

Thanks. That's what I get for using a 12 yo textbook. It used to work that way!