-----Original Message----- From: boost-bounces@lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Larry Evans
The 01.09.2006 04:12 ctor_template.zip file in the vault is my attempt at doing what you've outlined above. BTW, instead of something like the G macro, it uses:
g( BOOST_FWD_SEQ_FOR_EACH_IDENTITY ( (x) (y) ) )
Please let me know if you see any errors.
You can do it a little more efficiently regarding the comma handling. E.g. #define SEQ_FOR_EACH_IDENTITY(seq) \ BOOST_PP_SEQ_FOR_EACH_I(APPLY_IDENTITY, ~, seq) \ /**/ #define APPLY_IDENTITY(r, _, i, x) \ BOOST_PP_COMMA_IF(i) boost::forwarder::identity(x) \ /**/ You could also let the pp-lib do the work: #define APPLY_IDENTITY(s, _, x) boost::forwarder::identity(x) #define SEQ_FOR_EACH_IDENTITY(seq) \ BOOST_PP_SEQ_ENUM( \ BOOST_PP_SEQ_TRANSFORM(APPLY_IDENTITY, ~, seq) \ ) \ /**/ Either way, the speed difference between the above two is neglible for the number of arguments we're talking about (I tested up to 50).
The newest zip also includes a Makefile which I've found useful in seeing what's produced by cpp. I was wondering how you've gotten bjam to do something similar to that Makefile. If so, could you post the code or a link?
I don't use bjam for this. I run the compiler (or a set of compilers) in preprocess-only mode and look at the output. I make small proof-of-concept scenarios (regular code) in order to establish what I want to generate. Once I have decided that, then I write the generator and debug any errors I might have made. At this point, I'm specifically testing the generator--not the generated code. Once I'm satisfied that the generator is generating what I want, I then go on to full compiles and debugging the generated code. When I'm writing and testing the generator, I either do it outside of a normal "heavyweight" translation unit, or I comment out header inclusions that are not necessary for the generator itself--namely so I don't have to wade through enormous amounts of output to find my generated code. E.g. say I'm generating something that uses std::cout, when I'm writing and testing the generator, I'll comment out the inclusion of <iostream> because the generator itself doesn't need it to function. On most compilers, the preprocess-only command line switch is -E. Several compilers also support a -P command line switch that suppresses #line directives in the output and generally compacts vertical space. Regards, Paul Mensonides