On Mon, Sep 15, 2003 at 02:47:40PM +0000, Angus Leeming wrote:
> Andre Poenitz wrote:
>
> > On Mon, Sep 15, 2003 at 02:22:57PM +0000, Angus Leeming wrote:
> >
> > +struct Class { \
> > + /** The default argument is nasty, \
> > + * but allows us to use Class in STL containers. \
> > + */ \
> > + Class(Enum val = static_cast<Enum>(-1)) : val_(val) {} \
> > + operator Enum() const{ return val_; } \
> > +private: \
> > + Enum val_; \
> > +}
> >
> > If you don't like the default argument, why don't you use two
> > constructors?
> >
> > + Class() : val_(-1) {} \
> > + Class(Enum val) : val_(val) {} \
>
> Entirely reasonable. But also exactly equivalent. Or do I miss something?
Well... the compiler does not need to push an argument to the stack in
the default case and the cast is gone... So --- not _much_ difference.
>
> > I am not too fond of this macro business and I'd rather resort to a
> > separate LColor_enum.h header that contains this some 'ColorEnum' enum
> > only and include this header when it is needed. This would serve almost
> > the same purpose, wouldn't it?
>
> Alternatively, I could add this to LColor.h:
>
> class LColorEnum {
> // The default argument is nasty,
> // but allows us to use LColorEnum in STL containers.
> LColorEnum(LColor::color val = static_cast<LColor::color>(-1))
> : val_(val) {}
> operator LColor::color() const{ return val_; }
> private:
> LColor::color val_;
> };
Why to LColor.h and not to a separate header LColor_enum.h containing
enum ColorEnum {
/// No particular color---clear or default
none,
/// The different text colors
black,
///
white,
...
};
[In a namespace or not, or named 'color_none' or not, or...]
> Personally, I'm ambivalent. It seems to me that use of the macro to
> do this is safe and would save some lines of code if we were to use
> the same technique elsewhere. However, I do understand that macros are
> evil.
>
> How do you feel about this?
As I said, I'd prefer a de-coupled version without macros, but as I am
already a bit upset about people going into nitpick mode the final words
are:
I do not really care. Do whatever you want here, but do it quick, and go
back to solve serious problems afterwards.
Andre'
