Re: [boost] Re: Pretty Good Initialization Library

From: Dave Harris (brangdon_at_[hidden])
Date: 2004-07-07 18:00:05

In-Reply-To: <200407072103.i67L3Jk28273_at_[hidden]>
stewart_at_[hidden] (Rob Stewart) wrote (abridged):
> >     v << foo() << bar();
>
> I don't like that.  It suggests formatted insertion rather than
> initialization.

It's not intended to be initialisation. It does a push_back(), so you can 
do it at any time and not just on empty vectors. I guess I'd pick a 
different name for the library, but as written that includes += so it too 
is not just for initialisation.

As I said, I don't think formatting is an essential characteristic of 
operator<<(). It happens to be necessary for streams because they are text 
oriented. The serialisation library uses operator<<() without formatting.

> As you point out, conversion is possible, but one can't overload
> operator<< to customize the initialization.

Why not?

    vector<Foo> &operator<<( vector<Foo> &v, const Bar &bar ) {
        return v << bar.toFoo(); // Or whatever conversion you want.
    }

Or whatever the right types are.

> Thus, it doesn't fit neatly with IOStreams.

It's not polymorphic with them, but I think it fits about as neatly as the 
serialisation library.

-- Dave Harris, Nottingham, UK