[Boost-users] Re: Placeholder Arguments

From: David Abrahams (dave_at_[hidden])
Date: 2005-04-19 07:19:15

Joe McCay <joemccay_at_[hidden]> writes:

>      How do the placeholders actually get the arguments applied?  I
> have read through parts of the metaprogramming book and the
> documentation.  It's obvious to me how something like _1 (arg<1>)
> selects its argument.  I haven't been able to figure out is how it
> gets the arguments in the first place considering the Lambda
> expression is not something like _1(5) in most of the examples I have
> found.  My template skills are weak, and I am attempting to sharpen my
> them (and
> metaprogramming skills).

Are you asking about runtime lambda expressions as in the Boost Lambda
library, or compile-time lambda expressions as in MPL?

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com