[boost] [doc patch] clearification in conversion/cast.htm

From: Thorsten Ottosen (nesotto_at_[hidden])
Date: 2003-09-14 02:08:22

The following paragraph

-----------
The C++ built-in dynamic_cast can be used for downcasts and crosscasts of
pointers to polymorphic objects, but error notification in the form of a
returned value of 0 is inconvenient to test, or worse yet, easy to forget to
test. The polymorphic_cast template performs a dynamic_cast, and throws an
exception if the dynamic_cast returns 0.

-----------

should be extended with:

-------------

Moreover, polymorphic_cast is safer than a dynamic_cast using references
since it does not need to dereference the pointer. This means that the
casted pointer can be 0; in this case a dynamic_cast with references will
result in undefined behavior.

-------------

I've attached the new paragraph in html.

Thorsten Ottosen
----------------------------
Dezide Aps
www.dezide.com

begin 666 cast.html_patch.txt
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`
end