On 13/07/2017 23:17, Nicholas Devenish via Boost-users wrote:

With boost/rational.hpp, the code:

boost::rational<int> a{1}; long b{1}; auto c{a * b};

Works fine up to 1.63.0, but fails to compile in 1.64+ on the multiplication with "error: invalid operands to binary expression". This seems to be due to some restructuring that changed the way multiplications are declared, which (as far as I can tell), meant the operation declaration became conditional on number of representable digits.

This breaking change isn't listed on the release notes or the ::rational documentation, so I'm wondering if it was accidental and therefore a bug (whose behaviour might change), or a deliberate change to prevent downcasting and just undocumented?

That was my change - it was a bug fix, and actually brings the behaviour closer to what was always documented, in particular that accidental assignment from float's should be prohibited. At the same time I tightened up integer conversions so that "lossy" conversions have to be explicitly casted. And yes, it should have been documented... I'll sort something out for that. Best, John.

Nick

(I've come onto a project stuck on 1.56 and trying to update it) _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org https://lists.boost.org/mailman/listinfo.cgi/boost-users

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