Re: [Fresco-devel] Suggested addition to Coding Style-guide

Neil Pilgrim <[email protected]> writes:

| Gabriel Dos Reis wrote:
| > Neil Pilgrim <[email protected]> writes:
| 
| > |   class some_type;
| > |   namespace type_space
| > |   {
| > |     class some_type;
| > |   };
| > |   /* ... */
| [...]
| > | In quite a few instances (if not a *lot*!) we don't currently do this;
| > | it seems like a good common idea, so assuming no discussion to the
| > | contrary it'd be good to add it to the coding guide. Oh, and implement
| > | it ;)
| [...]
| 
| > I would suggest you don't repeat declarations all over the places as
| > suggested above.
| > While that might be seem a reasonable practice in C, it is recommanded
| > for C++ coding that you :
| > 
| >    (a) include the appropriate header files
| >    (b) design a forward-declaration header and do (a)
| > 
| > The point is that C++ tends to be very picky about declarations and
| > name-lookup are already complicate; it is better to include a heade
| > file that provides the "true" declarations in every translation unit.
| > 
| > You'll also find that what you're proposing does not scale to standard
| > types and functions.  It is therefore preferable to have a coding
| > style that apply both to standard headers and Fresco entities.
| 
| This may be ideal, but then surely you either a) end up having a huge
| number of files (one per previous header?) b) one per section?

Note necessarily. Usually, one creates a file with forward-declarations
of logically *releated* classes and types.

[...]

| Maybe build times cannot be drastically reduced with this method, but in
| my limited experience it can be very useful in limiting the dead time
| during development.

When build times is really an issue, I believe using that using things
like precompiled headers helps much more than declaring by hand which
entity one uses.  At least, that is my exprience with large projects.

A frightening downside of forward declaring "by hand" is the same as
why you don't want code-duplication: Every minor change needs to be
done at zillions of places, whereas including a forward declaration
header keeps the changes in one place.

-- Gaby