How to check a struct exists at a particular memory address?

[Gary Willoughby via Digitalmars-d-learn]

On Thursday, 18 May 2017 at 21:09:06 UTC, Igor wrote:
> On Thursday, 18 May 2017 at 20:20:47 UTC, Gary Willoughby wrote:
>> This might be a really silly question but:
>>
>> I've allocated some memory like this (Foo is a struct):
>>
>>     this._data = cast(Foo*) calloc(n, Foo.sizeof);
>>
>> How can I then later check that there is a valid Foo at 
>> `this._data` or `this._data + n`?
>
> Well... I think the right answer is that everything you do with 
> memory should be very deterministic so you should just know 
> where is what and not have a need to check :).

Agreed. I think I'll re-visit the design.