pointer check in unit tests

[Stephan Bergmann]

On 04/11/2020 11:35, Mike Kaganski wrote:
> On 04.11.2020 12:51, Stephan Bergmann wrote:
>> On 04/11/2020 08:26, Miklos Vajna wrote:
>>> If a never-nullptr pointer is returned, it would be really useful to
>>> somehow state that in the function's signature. Are you aware of any way
>>> to do that? There is C's __attribute__((nonnull)), but it only works on
>>> function parameters, I think.
>>
>> see "not_null" at 
>> <https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines>
> 
> The note in F.60 that reads:
> 
>> Note If you prefer the pointer notation (-> and/or * vs. .), 
>> not_null<T*> provides the same guarantee as T&.
> 
> looks to me as if T& still *does* mean "pointer, but not null, with a 
> special syntax".

...the same guarantee that "no argument" is not a valid option, is 
presumably what that note wants to express in the context of "F.60: 
Prefer T* over T& when 'no argument' is a valid option".

That a reference is something completely different than a pointer shows 
e.g. in the rule that if a class has an implicit copy constructor and a 
non-static data member of reference type, then the copy constructor is 
defined as deleted (while there is no such rule if the data member is of 
pointer type).