• Tofu Ninja (12/12) Feb 13 2016 Is the TypeInfo given by typeid() guaranteed to be the same for a
• Benjamin Thaut (9/21) Feb 13 2016 Yes, type infos are garantueed to have identity. You can use

Tofu Ninja <emmons0 purdue.edu> writes:

Is the TypeInfo given by typeid() guaranteed to be the same for a 
type regardless of where I call it? I guess my question is, is 
the TypeInfo a valid way to dynamically check types?

I am implementing a message passing system for an 
entity-component system, I was planning to use structs as 
messages and use the TypeInfo to determine where they are 
supposed to go. Will this cause any problems?

Also will typeid() allocate? Or is the TypeInfo statically 
allocated at compile time?

Also how does shared libs affect this? Will a TypeInfo passed 
across different libs still match up?

Thanks

Benjamin Thaut <code benjamin-thaut.de> writes:

On Saturday, 13 February 2016 at 12:44:40 UTC, Tofu Ninja wrote:
 Is the TypeInfo given by typeid() guaranteed to be the same for 
 a type regardless of where I call it? I guess my question is, 
 is the TypeInfo a valid way to dynamically check types?

 I am implementing a message passing system for an 
 entity-component system, I was planning to use structs as 
 messages and use the TypeInfo to determine where they are 
 supposed to go. Will this cause any problems?

 Also will typeid() allocate? Or is the TypeInfo statically 
 allocated at compile time?

 Also how does shared libs affect this? Will a TypeInfo passed 
 across different libs still match up?

 Thanks

Yes, type infos are garantueed to have identity. You can use 
their adress to identify a type.

The linux shared library mechanism ensures that they have the 
same adress across multiple shared libraries (if all of these 
libraries are loaded into the same process)

With windows dlls there can be cases where a typeinfo is 
duplicated. But as dlls don't really work yet, I wouldn't worry 
about it.