Re: Performance cost of RTTI vs programmed type system
On 2008-08-07 00:56:58 -0400, Mathias Gaunard <loufoque@gmail.com> said:
On 6 ao?t, 21:58, Pete Becker <p...@versatilecoding.com> wrote:
On 2008-08-06 04:28:24 -0400, Mathias Gaunard <loufo...@gmail.com> said:
On 5 ao?t, 23:28, Eugene Gershnik <gersh...@gmail.com> wrote:
IIRC GCC uses plain pointer comparisons so on this compiler RTTI won't
work reliably across shared libraries. OTOH such implementation is
probably as fast as a manual scheme.
I don't know much about shared libraries/DLLs, but why is it a
problem?
Sometimes the compiler generates separate RTTI objects in different
DLLs for the same type.
I see.
Simple fix: don't compare instances of types that you want to identify
at runtime that weren't created in the same DLL.
That doesn't seem like a very serious limitation to me.
Well, it is. <g> For example, catching an exception with someting other
than ... depends on being able to identify its type. But again: there's
no inherent reason this can't be done right.
--
Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com) Author of "The
Standard C++ Library Extensions: a Tutorial and Reference
(www.petebecker.com/tr1book)
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