class.sizeof

[Denis Koroskin]

On Fri, 14 Nov 2008 21:06:39 +0300, Tomas Lindquist Olsen  
<tomas at famolsen.dk> wrote:

> Denis Koroskin wrote:
>> I can't find a way to get a class sizeof property - it returns 4 (32bit  
>> pointer size) always. I tried many ways but still can't figure out how  
>> to do this. Documentation says that
>>  ".sizeof applied to a class object returns the size of the class  
>> reference, not the class instantiation."
>>  Is it possible? Any idea is much appreciated.
>
> No nice way to do it..
>
> auto sz = myclass.classinfo.init.length;
>
> problem this is not a compiletime constant,
>
> In D2 you can use __traits to get it...
>
> Kinda lame if you ask me :P
>
> how about .instancesizeof ? I doubt that's even a remotely common  
> variable name ...
>
> -Tomas

__traits trick works nice, thank you!

BTW, I found small inconsistency/bug:

template SizeOfPointee(T)
{
     static if (is (T t)) {
         enum SizeOfPointee = typeof(*t).sizeof;
     }
}

template SizeOfPointer(T)
{
     static if (is (T t)) {
         enum SizeOfPointer = typeof(t).sizeof;
     }
}

int i = SizeOfPointee!(int*); // works ok
int j = SizeOfPointer!(int*); // fails

I believe both should work.