C++ delete쓸때 NULL체크 하지말자!!!

[16.7] Do I need to check for NULL before delete p?
No!

The C++ language guarantees that delete p will do nothing if p is equal to NULL. Since you might get the test backwards, and since most testing methodologies force you to explicitly test every branch point, you should not put in the redundant if test.

Wrong:
if (p != NULL)
delete p;

Right:
delete p;

http://www.parashift.com/c++-faq-lite/freestore-mgmt.html#faq-16.7

One must write good code. One must write perfect code. One must write as efficient code as possible. One thing which amazes me is that there are number of people out there in C++ world who''re still checking for pointer being NULL (0) before deleting it. Here''s the pseudo-code:


void Foo()
{
CBar *pBar = new CBar();

// Do something with pBar (validate, use) ...

if (0 != pBar)
{
delete pBar;
}
}

Please don''t do this, you can omit the if-statement and just delete the pointer. Everything will be fine. Additional lines of code only: a) make life harder for the people who have to review your code; b) decrease your code coverage numbers; c) demonstrate that you don''t know the language basics.

The obvious places for answers are:

- "Freestore management section" of C++ FAQ
- C/C++ Language Reference in MSDN

For C people - yes, the same applies to free() also, no need to check for NULL. Check out also a draft rationale for the C99 standard. One thing to keep in mind though is that this information is Microsoft-centric, please check the documentation for your compiler first.

단, 클래스에서 new delete를 재정의해야만 쓸수있는 Brew같은 플랫폼에서는 NULL체크를 해주어야 된다.

delete 오버라이딩할때 널체크를 해줘서 널체크를 빼 주는것도 나쁘지 않을듯...

p.s 예전에 올렸던건데 혹시나 아직 못보신 분들을 위해서...