Re: [ANN] Lua 5.2.1 (work1) now available

[liam mail <liam.list@...>]

On 7 April 2012 17:29, Coda Highland <chighland@gmail.com> wrote:
> On Sat, Apr 7, 2012 at 11:07 AM, Patrick Rapin <toupie300@gmail.com> wrote:
>>> This HAS to be a reinterpret_cast because all casts through void* are
>>> considered unsafe by the compiler.
>>
>> Sorry, but this is wrong.
>> A compiler will generate error when using static_cast to convert
>> between *unrelated* pointer types.
>> The generic void* pointer is considered related with all T* pointers
>> (without const or volatile qualifier).
>> Also, the cast from A* to B* is accepted by static_cast if B derives
>> from A (the other way round, converting B* to A* does not need any
>> cast of course).
>
> I'd still make it a reinterpret_cast even if the compiler allows it
> because I disagree with the notion that void* is related. It really is
> a reinterpretation of the pointer -- from a known type to an opaque
> one. It's not becoming more or less specific like a static_cast would
> imply; it's completely losing all of its type information. So spec or
> not, the idea of what the casts are supposed to be makes void*
> conceptually a reinterpret_cast even if the compiler allows
> static_cast.
>
> /s/ Adam
>

Whether you agree of not does not really matter,static_cast is the
correct cast to use and the result of reinterpret_cast is mostly
implementation specific.

Liam