TITLE: notes on type_info

(Newsgroups: comp.std.c++, 2 Jun 98)

ODA: "HiroshiOda" <HiroshiOda@root.or.jp>

>Why the class std::type_info is designed to be prevent copying?


CLAMAGE: stephen.clamage@Sun.COM (Steve Clamage)

To allow implementors maximum freedom in the implementation, and
because there doesn't seem to be any need for copies. In particular,
you can get only pointers and references to a type_info object,
and the actual object might be of a class derived from type_info.
If you could copy it, you'd get a slice, which would not have
the same properties as the original.

ODA:

> ... I'm not sure which we may
>assume the return value of typeid() refers to something of temporary object
>or global static object. 

CLAMAGE:

The lifetime of a type_info object is required to extend to the end
of the program. You can safely keep pointers and references to the
original object.