/* constrained_value.hpp Boost constrained_value type mini-library original authour: Jeff Garland, http://www.crystalclearsoftware.com/ modified by: Christopher Diggins http://www.cdiggins.com license available at http://www.boost.org/LICENSE_1_0.txt last modified: May 16, 2004 */ #ifndef BOOST_CV_HPP #define BOOST_CV_HPP // you can explicitly turn off constrained_value_checking #ifdef BOOST_CV_CHECKING_OFF #define BOOST_CV_CHECKING_ON 0 #else #define BOOST_CV_CHECKING_ON 1 #endif #include <boost/mpl/if.hpp> namespace boost { namespace cv { enum enum_violation { min_violation, max_violation }; template<typename T, T min_T, T max_T> struct integer_range_policy { typedef typename T value; static const value min() { return min_T; }; static const value max() { return max_T; }; }; struct default_error_policy { template<typename T> static void on_error(T value, T* field, T min, T max, enum_violation v) { throw; } }; template < class constraints_policy, class error_policy = default_error_policy, bool implicit_conversion_policy = true > class constrained_value { private: struct unused_struct { }; public: typedef constrained_value<constraints_policy, error_policy, implicit_conversion_policy> self; typedef typename constraints_policy::value value; typedef typename mpl::if_c<implicit_conversion_policy, value, unused_struct> value_parameter; constrained_value() : m(min()) { } constrained_value(const self& x) { m = x.get_value(); } constrained_value(value_parameter x) { assign(x); } static const value min() { return constraints_policy::min(); } static const value max() { return constraints_policy::max(); } const value get_value() const { return m; } operator value() { return m; } self& operator=(const self& x) { m = x; return *this; } self& operator=(value_parameter x) { assign(x); return *this; } void assign(unused_struct x) { } void assign(const value& x) { #ifdef BOOST_CV_CHECKING_ON { // +1 removes unsigned warnings if (x+1 < min()+1) { error_policy::on_error(x, &m, min(), max(), policies::min_violation); return; } if (x > max()) { error_policy::on_error(x, &m, min(), max(), policies::max_violation); return; } } #endif m = x; } private: value m; }; }; }; #endif // BOOST_CV_HPP