Le mar 24/02/2004 à 02:58, Eric Niebler a écrit :
John Maddock wrote:
Would you like to make and manage the change? Remove the workarounds from win32.hpp, and then patch all occurrences of min and max throughout boost?
John.
<recap> We agreed to make boost work in the presence of the min/max macros by wrapping all min/max function identifiers in parens, like (std::min)(a,b); </recap>
Could you be a bit more precise about these modifications? I find this "800" number quite huge. How did you deal with occurrences of min and max that rely on ADL (sorry if that is not the correct term)? Or did you handle only explicitly qualified calls std::min and std::max? I'm asking because the Interval library relies on this kind of construct in order to deal with built-in types (like int, float, etc) and user-defined types (their min and max are found by Koenig lookup). I know David Abrahams was recently suggesting to redefine functions in their original namespace; but in the meantime, it is still common practice to disallow any user definition in the std namespace. Here is a small example: #include <algorithm> // defines std::min template< class T > void f(T const &a, T const &b) { using std::min; min(a,b); } namespace n { struct c {}; void min(c const &a, c const &b) { throw; } } int main() { n::c a; f(0, 0); // should call std::min f(a, a); // should call n::min } This code compiles as expected. However, if you replace "min" by "(min)" and use GCC 3.4, it doesn't work anymore: f(a,a) will try to use std::min. It seems to me that GCC 3.4 behaves accordingly to the standard and that the second version of min can't be found if min is wrapped in parentheses. So, which modification did you use in this case? Sorry for the noise if the answer is trivial or if you didn't modify this kind of construct. Regards, Guillaume
I have spent some time and made the 800 or so edits throughout boost required to make it play nice with the min/max macros. I'm running regressions now. I have a couple of questions about procedure before I can commit the changes.
1) Is this a good time? I know there's talk about a 1.31.1 release. Will this be done from the 1.31.0 branch or from main? I don't want to destabilize before a release.
2) I can't test with old compilers, which are the ones most likely to have a hard time with this change. Also, I'm not a CVS guru. If all hell breaks loose as a result of this change, is there someone willing to help me back it out?
3) Is there a boost developer style guide where we can document the fact that all calls to min/max functions must be wrapped in parens?
4) This is the sort of thing developers will forget to do even if it's in a style guide. A simple way of ensuring this stays fixed would be to run the regressions with min() and max() #defined to garbage, so that violations are detected and corrected early. Is this possible?
Thanks.