David Abrahams wrote:
Edward Diener <eddielee@tropicsoft.com> writes:
Maybe that wasn't the best choice of words. I just meant that we'd lose the functionality provided by BOOST_WORKAROUND if we started using the macros you suggest instead.
We would not so much as lose the functionality as offer a more simplistic and readable way to express it. My suggestion is just about readability. When I see:
#if BOOST_WORKAROUND(nnnn,comparison operator)
I often can not tell to what it refers without some comment. But if I saw, as an example:
#if BOOST_COMPILER_VC71
it becomes easier to understand.
You obviously didn't read the entire comment in workaround.hpp then. #if BOOST_COMPILER_VC71 can't support BOOST_DETECT_OUTDATED_WORKAROUNDS.
You mean the BOOST_TESTED_AT syntax ? No, it does not support that. However one could create a series of macros, let us say for VC71, like this: // These are always defined and included in a header file at the top of select_compiler_config.hpp #define BOOST_COMPILER_VC _MSC_VER #define BOOST_COMPILER_VC71_VERSION (1310) #define BOOST_COMPILER_VC71_VERSION_HIGH (1310) // This would be different for a later service pack of VC71 which had a higher _MSC_VER, and is the only define that might ever need to be changed for this compiler/version // These are defined as 0 unless the Microsoft compiler header is selected in which case the definitions below are in a header file at the top of visualc.hpp #define BOOST_COMPILER_VC71_OR_HIGHER (BOOST_COMPILER_VC >= BOOST_COMPILER_VC71_VERSION) #define BOOST_COMPILER_VC71_OR_LOWER (BOOST_COMPILER_VC <= BOOST_COMPILER_VC71_VERSION_HIGH) #define BOOST_COMPILER_VC71 (BOOST_COMPILER_VC71_OR_HIGHER && BOOST_COMPILER_VC71_OR_LOWER) You could now say: #if BOOST_WORKAROUND(BOOST_COMPILER_VC,BOOST_COMPILER_VC71_VERSION) // code #endif or, in a different situation: #if BOOST_WORKAROUND(BOOST_COMPILER_VC,BOOST_TESTED_AT(BOOST_COMPILER_VC71_VERSION_HIGH)) // code #endif or, in a different situation: #if BOOST_COMPILER_VC71 // and any other combinations you like // code #endif etc. If you are arguing for only using BOOST_WORKAROUND, and never using a construct like the last one, then you are advocating always using specific version numbers. In that case you may want to consider at least forms like BOOST_COMPILER_VC71_VERSION and BOOST_COMPILER_VC71_VERSION_HIGH useful for your BOOST_WORKAROUND and BOOST_TESTED_AT macros. Of course you would have the same macros for each compiler/version, as an example with BORLAND instead of VC, __BORLANDC__ instead of _MSC_VER. and BCB6 instead of VC71. I am sure you get the idea. For BCB6 it would like like this: // These are always defined and included in a header file at the top of select_compiler_config.hpp #define BOOST_COMPILER_BORLAND __BORLANDC__ #define BOOST_COMPILER_BCB6_VERSION (0x560) #define BOOST_COMPILER_BCB6_VERSION_HIGH (0x564) // this is the only define that might ever need to be changed for this compiler/version // These are defined as 0 unless the Borland compiler header is selected in which case the definitions below are in a header file at the top of borland.hpp #define BOOST_COMPILER_BCB6_OR_HIGHER (BOOST_COMPILER_BORLAND >= BOOST_COMPILER_BCB6_VERSION) #define BOOST_COMPILER_BCB6_OR_LOWER (BOOST_COMPILER_BORLAND <= BOOST_COMPILER_BCB6_VERSION_HIGH) #define BOOST_COMPILER_BCB6 (BOOST_COMPILER_BCB6_OR_HIGHER && BOOST_COMPILER_BCB6_OR_LOWER) You could now say: #if BOOST_WORKAROUND(BOOST_COMPILER_BORLAND,BOOST_COMPILER_BCB6_VERSION) // code #endif or, in a different situation: #if BOOST_WORKAROUND(BOOST_COMPILER_BORLAND,BOOST_TESTED_AT(BOOST_COMPILER_BCB6_VERSION_HIGH)) // code #endif or, in a different situation: #if BOOST_COMPILER_BCB6 // and any other combinations you like // code #endif etc. All of this is syntactic sugar so that the BOOST_WORKAROUND, BOOST_TESTED_AT, or the raw #if versiontag op nnnn, is more readable.