On 17.12.2012, at 07:00, Nathan Ridge wrote:
Perhaps the config library authors can confirm whether my speculation about the rationale is correct.
My guess would be that in addition to your reasons, it's a matter of implementation. If standard feature support macros are positive, for the implementation it either means - having every compiler/stdlib config header define every single feature macro, which is a lot of syntactic overhead (i.e. greater risk of stupid mistakes like forgetting one, slightly more work when adding a new platform, and of course the annoying fact that when adding a new perfectly compliant platform, "do nothing" is not the right thing to do) or - having a core header that defines every single macro, and then have the specific headers undefine them as needed, which strikes me as needlessly complicated. Also, it means a slight parsing overhead over just not having any code for features that are supported. Sebastian