Hello, I am building an app for IOS (ARM) and I had this issue while compiling: *Boost.Numeric.Interval: Please specify rounding control mechanism.* C99 version should be used in this case but __USE_ISOC99 is not defined. Modifying the condition with this code (using __cplusplus) fixed the issue: *boost/numeric/interval/hw_rounding.hpp(36)* *#if defined(BOOST_NUMERIC_INTERVAL_NO_HARDWARE) && (defined(__USE_ISOC99) || defined(__MSL__) || (defined __cplusplus && __cplusplus >= 201103L))# include #endif* Let me know if I missed something or if you plan to integrate this modification in a next version. Cheers, Bastien Commelongue -- [image: UVI] http://www.uvi.net/ Bastien Commelongue | Software Development A. 159 rue Amelot - 75011 Paris - France T. 0033671833955 • M. b.commelongue@uvi.net [image: Facebook] http://www.facebook.com/UVI.Official [image: Twitter] http://twitter.com/UVIofficial [image: Youtube] http://www.youtube.com/user/UVIofficial [image: SoundCloud] http://soundcloud.com/uvi-official [image: Instagram] http://instagram.com/weareuvi/