why to avoid check for null after new as per ISO C++

Question

ISO C++ says...

Fred * p = new Fred();  // No need to check if p is null

No need to check p for null why is that so ?

Its explained @ source: https://isocpp.org/wiki/faq/freestore-mgmt#new-never-returns-null — Alex K., May 19 '15 at 14:38
`new` can only return `nullptr` if you have `new (std::nothrow) Fred()`. — David G, May 19 '15 at 14:39
https://stackoverflow.com/questions/550451/will-new-return-null-in-any-case — Cory Kramer, May 19 '15 at 14:43

score 12 · Answer 1 · answered May 19 '15 at 14:37

The reason is that this type of call to new results in an exception being raised if there is a memory allocation error. So there is no situation in which new would return NULL/nullptr when invoked like this.

It you want new to return NULL instead of throwing an exception, you can invoke it with std::nothrow:

Fred* p = new (std::nothrow) Fred();

Here, it would make sense to check against NULL/nullptr.

why to avoid check for null after new as per ISO C++

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