Re: [boost] metactrl header [was Smart Pointer...]

From: Beman Dawes (beman_at_[hidden])
Date: 2000-07-18 12:31:17

Jeremy, or anyone else with ideas,

One thing that is missing, both from boost and metactrl, is compile time 
error detection and reporting.

I've been trying to write an experimental generator, and the need to report 
that an invalid configuration has been detected pops up right away.

There have been a number of boost discussions and proposals for 
compile_time asserts, and I guess if any of them work well with template 
metaprogramming, we should dust them off for inclusion.  But the concern 
here is just template metaprogramming, so a solution that worked only in 
that limited context would be OK.

While the example C&E give on page 622 results in a fairly clear compiler 
error message, it takes quite a bit of coding to implement. If the 
difficulty of reporting errors causes generator programmers to skip error 
checks, that is a "bad thing".  Any library support would be certainly be 
appreciated.

--Beman