Hello all, Boost.Contract allows to specify "assertion requirements": /assertion-condition/, requires /assertion-requirement/ If the requirement is not met then the assertion condition is neither compiled nor checked at run-time. Question: Shall the assertion-requirement be a nullary boolean meta-function or just a static boolean value? For example: CONTRACT_FUNCTION( template( typename T ) requires( boost::LessThanComparable<T> ) (T const&) (min) ( (T const&) x, (T const&) y ) postcondition( auto result = return, x < y ? result == x : result == y, requires boost::has_equal_to<T>::value // static boolean ) ) { return x < y ? x : y; // OK: T is less than comparable `<`. } For now, the assertion requirement is a static boolean value so it can be more easily manipulated (using !, &&, ||, etc instead of mpl::not, mpl::and, mpl::or, etc). However, is there any strong reason for marking the assertion requirement a nullary boolean meta-function instead like the following code? x < y ? result == x : result == y, requires boost::has_equal_to<T> // meta-function Thanks. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-contract-assertion-requirements-as-... Sent from the Boost - Dev mailing list archive at Nabble.com.