Re: [Boost-users] Is it a good style about boost::format( format-string ) % arg1 % arg2 % ... % argN

On Thu, 12 Oct 2006 03:20:33 +0800, Aaron Griffin wrote:

On 10/11/06, William Xue wrote:

...

First, I am a new user of boost. I wonder of the style of 'boost::format( format-string ) % arg1 % arg2 % ... % argN'. I think it, format(...), as a function, but it seems not function in C or C++ style.

variable arguments are very nasty in C++. Not only that, but the va_* macros do not allow for type safe generic programming (or type safety in general).

The way it works is that boost::format("..."); returns an object which has the % operator defined. object % <anything> performs the operation and returns the same object. This allows for chaining.

Thank you very much! Your explanation is very clear. I am agree with you, it's nasty. As someone had said, the style smelt very bad. Though C/C++ is very flexible, I do not like to broke the regular rules of them. Micrisoft have done something like this in their sample codes: ---8<--------------------------------------------->8--- #define PURE =0 ... interface xxx { ... int foo(...) PURE; ... }; ---8<--------------------------------------------->8--- I can not to find out any wisdom in doing things like this. As a C/C++ user, I am very glad to see someone to extend the features of them, But IMHO, C/C++ is C/C++, do not go far away from the regular way. Again, thanks.

I'd assume the goal is to mirror python syntax.

The problem with something like this: boost::format("...") % (a,b,c,d); is that C++ does not allow it. It is not syntactically correct. _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

-- Sincerely yours, William