Re: [boost] [config][mpl][type_traits][integer] BOOST_STATIC_CONSTANT should use constexpr

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#ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION template bool const ice_eq::value; // ********* template bool const ice_ne::value; // ********* #endif

for which I have needed to change const by BOOST_CONSTEXPR_OR_CONST. <...> What am I missing?

Looks like it shall be #ifdef BOOST_NO_INCLASS_MEMBER_INITIALIZATION not #ifndef

But how did it work before? Or nobody tested it on ancient compilers?

No that's correct as is: * if BOOST_NO_INCLASS_MEMBER_INITIALIZATION is defined, then the constant is really an enum and there should be no out-of-line definitions. * if BOOST_NO_INCLASS_MEMBER_INITIALIZATION is *not* defined, then the constant *should* have the out-of-line definition in case it's address is taken/used. As for the original question, this is such a pervasive breaking change, I think a new macro is inevitable I'm afraid :-( John.