Re: [boost] Re: Variant (aka Discriminated Union) implementation

From: David Abrahams (david.abrahams_at_[hidden])
Date: 2002-06-26 10:01:18

----- Original Message -----
From: "Andrei Alexandrescu" <andrewalex_at_[hidden]>

> On a related note, looking at the implementation reinforces my impression
> that programming with mpl is more trouble than it's worth. After
including
> 13 (!) mpl headers, the net benefit is that more code must be written
with
> mpl than without. For example, computing the maximum sized type in a
> typelist takes 26 non-blank lines, while the vanilla MaxSize takes 16
lines
> to do the same task. I didn't run a full analysis, but my impression
after a
> couple of reads is that the difference in source file sizes (783 vs. 573
> lines) is partly due to using mpl.

I'm very surprised to hear that. This example is from the MPL paper:

mpl::max_element<Sequence,
    mpl::less<mpl::size_of<_1>, mpl::size_of<_2> > >::type

-Dave