Re: [Boost-users] Re: [MPL] replace_if question

David Abrahams wrote:

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{ replaceit< vector< charm

You should be seeing a syntax error right here.

:) I'll admit I had to patch something up in the e-mail. Obviously I mistyped.

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What's the right way to do this?

Use an algorithm like transform that _computes_ the new values rather than simply replacing them with a constant value:

Ok, thanks. I have to read some more to better understand which algorithms operate on constants and which invoke metafunctions. I should have been clued in by the name to look up the STL version.

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Furthermore, is there a better way to identify pairs in replace_if than deriving from a special class? All I can think of is writing a predicate class and specializing it for mpl::pair. Seems like there should be an easier way.

Why? That seems like a pretty darned good approach to me.

I guess it didn't feel like the "mpl way" to me. I remember back when MPL was first being discussed that the STL-ness of it was compared to the pattern-matching approach of Loki. I was a doubter about the STL-ness but now that I've used it some I'm warming up to it. :) Thanks again. I'm slowly climbing the curve... -Dave