Re: question about nullptr

On 06/07/2024 17:57, David Brown wrote:

On 06/07/2024 16:39, Richard Damon wrote:

On 7/6/24 7:49 AM, Thiago Adams wrote:

If you were creating C code today and could use a C23 compiler, would you use nullptr instead of NULL?
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I am asking because I think I will keep using NULL.
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I like nullptr semantics but I don't like to introduce new element (nullptr) inside the code with no guarantee that the code will not mix both.
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In the past we also didn't have a guarantee we are not mixing 0 or NULL.
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I think the best scenario for a team guideline would be a style warning if 0 or nullptr is used and NULL to be defined as nullptr in a C23 compiler.
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The (small) problem with 0 or NULL being use is that in a context where you THINK you are passing a pointer, but the function actually is taking an integer value, 0 or NULL (defined as a 0) passes the syntax check.
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If C23 REQURIED NULL to be defined as nullptr, then NULL would have been used, but as far as I know, it is still allowed to be defined as 0 (unless you also have POSIX compatibility).
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With POSIX Compatibility, where NULL must have the type of (void*) you also avoid the possible error, and thus the desire to use nullptr.

 I hope that defining NULL as nullptr will become common - but I would be surprised to ever see it being required by C standards.
 The ideal would be for C libraries to define NULL as nullptr and for C compilers to support a flag like gcc's "-Wzero-as-null-pointer-constant" warning (it is currently C++ only).  Then people can easily eliminate
any mixup between integer 0 and null pointer constants by using that flag and either NULL or nullptr, according to taste.  (And those who don't want such checks, are not required to change.)
 

So, if malloc was changed to 'returns nullptr and sets errno on error', will you still be able to say:
if ( p == NULL ) ...
if ( !p ) ...
?