Re: [Boost-users] [mpl] BOOST_MPL_AUX_LAMBDA_SUPPORT for classes without nested ::type

From: David Abrahams (dave_at_[hidden])
Date: 2007-07-26 10:49:03

on Thu Jul 26 2007, Joaquín Mª López Muñoz <joaquin-AT-tid.es> wrote:

> whereas the code associated with bar<> works OK. So, it seems like
> BOOST_MPL_AUX_LAMBDA_SUPPORT does not provide lambda
> support for classes without nested ::type:

Right.  

>   1. Is this so by design 

Sorta.  Support for classes without nested type is a convenience for
people who need to generate foo<T> where foo is a 3rd-party template
on which one can't intrude, so they don't need to write a make_foo<T>
metafunction that produces foo<T>.  Presumably if you can intrude on
the class to add BOOST_MPL_AUX_LAMBDA_SUPPORT, you can also intrude to
add a nested ::type.

> and/or documented somewhere?

Probably not.

>   2. If not, could it be fixed?

I don't know; if you come up with a fix that doesn't break anything
else, I'd encourage Aleksey to at least consider it.  I don't consider it a
high enough priority to search for a fix myself.

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com
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