On Friday, 4 March 2016 at 15:18:55 UTC, Steven Schveighoffer
wrote:
On 3/3/16 6:58 PM, Yuxuan Shui wrote:
On Thursday, 3 March 2016 at 23:51:16 UTC, Adam D. Ruppe wrote:
On Thursday, 3 March 2016 at 23:46:50 UTC, Yuxuan Shui wrote:
Will typeid(a) is typeid(b) yield different results than
typeid(a) ==
typeid(b)?
No. Indeed, opEquals on TypeInfo just calls is itself.
But opEquals also has extra comparison:
auto ti = cast(const TypeInfo)o;
return ti && this.toString() == ti.toString();
This makes me feel they are not the same.
In some cases, for instance using DLLs, the TypeInfo for an
object allocated in one way may be identical, but be a
different instance from the TypeInfo allocated in another way.
This is why the string comparison occurs.
Note that comparing ANY object will first check if they are the
same instance before calling any functions (this is in
object.opEquals)
-Steve
Thanks for answering. But I still don't understand why TypeInfo
would need to be allocated. Aren't typeid() just returning
references to the __DxxTypeInfo_xxxx__initZ symbol?
