Experimental Physics and
Industrial Control System

Kay-Uwe Kasemir <[email protected]> · Tue, 27 Sep 2005 15:18:13 -0400

Hi:
On Sep 27, 2005, at 14:47 , Jeff Hill wrote:

PropertyCatalog currently has "operator =" and "operator ==".

O Do they meet the conventional wisdom test? That is, is their purpose

roughly equivalent to the purpose of these operators with primitive

types?

The '=' is supposed to be a simple assignment.
Something that can usually be done in one machine-code instruction.
Maybe a memcpy or double-to-int conversion.
Not invocations of traverse(), looking for matching properties
via find(), converting types, ...
Such a rather complex mapping exceeds what I'd expect
behind a simple '='.

I think "The C++ Programming language" has a discussion
for iterators, operator ++.
If it's a constant-speed iteration, like an in-memory linked list:
OK.
Not OK for remote database access where one '++' returns immediately,
the next one takes a minute.

-Kay

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System