[Boost-users] Re: MPL Library

Cromwell Enage wrote:

Hello, there!

--- Edward Diener wrote:

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I have bit the bullet and am attempting to get my head around the MPL library. I realize there is a book out by Messieurs Abrahams and Gurtovoy, I believe, but I thought I would tackle the boost documentation first. A few questions:

1) Is the documentation up to date?

Not yet.

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2) There are three separate documents to study, it seems, all giving information about the MPL library, a white paper circa 2002, a reference, and a mini-tutorial. Is the information in these in sync with each other?

Not yet. The differences between the MPL version described in the white paper and the new one described in the reference are summarized at http://www.mywikinet.com/mpl/mpl_1_32_changelog.html.

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The reason I ask is that the white paper/mini-tutorial mentions if_<> and apply_if<> but the reference does not mention them at all. Are they just understood intrinsic metafunctions that need no reference, or what?

The reference itself is not yet finished. The white paper will stand you in good stead wrt these two metafunctions, as long as you replace all instances of apply_if with eval_if, as per the changelog.

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3) A number of the topics in the reference documentation mentioned in generalized overviews of the various sections have no specific links. Does this mean that they were never implemented? Seems dubious in a number of cases.

Mostly it's as I said above: unfinished reference docs. However, I'm trying to help out with at least one topic--rational constants--that is not yet implemented.

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I would seriously like to figure out how MPL works and play around with it, but I feel stymied with what is in the boost docs.

Yeah, most of the knowledge I've acquired about MPL so far came from studying the headers and playing with the various metafunctions. Right now I'm treating the boost docs as supplemental aids.

Let me know how I can help further!

Thanks for your offer of help. I am going to wait until Mr. Gurtovoy has finished updating the docs until I tackle learning and using the library. When I do, and post any questions on usage here, if you see them and can help me out with your experience, it will be greatly appreciated.