[Olena-patches] 3392: Add sample code of 'inf' for Fred.

https://svn.lrde.epita.fr/svn/oln/trunk/milena/sandbox Index: ChangeLog from Thierry Geraud &lt;thierry.geraud(a)lrde.epita.fr&gt; Add sample code of 'inf' for Fred. * theo/csi: New directory. * theo/csi/fred.cc: New. fred.cc | 148 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) Index: theo/csi/fred.cc --- theo/csi/fred.cc (revision 0) +++ theo/csi/fred.cc (revision 0) @@ -0,0 +1,148 @@ +#include <mln/core/concept/function.hh> +#include <mln/core/concept/value.hh> +#include <mln/fun/internal/resolve.hh> + + +namespace mln +{ + + + // Forward declaration. + namespace fun { + namespace vv2v { + template <typename T> struct inf; + } + } + + + namespace trait + { + + // Default (whatever the category): + // "inf" performs a "min"! + template <template <class> class Category, typename T> + struct set_unary_< fun::vv2v::inf, Category, T > + { + typedef set_unary_< fun::vv2v::inf, Category, T > ret; + + static T exec(const T& t1, const T& t2) + { + return t1 < t2 ? t1 : t2; + } + + // In the case of a binary function with two different argument + // types, we shall instrument this definition with the result + // type... + }; + + } // mln::trait + + + + namespace fun + { + + namespace vv2v + { + + // fun::vv2v::inf<T> + + template <typename T> + struct inf : Function_vv2v< inf<T> > + { + typedef T result; + + typedef mln_fun_internal_resolve(inf) impl; + + T operator()(const T& t1, const T& t2) const + { + return impl::exec(t1, t2); + } + }; + + + // fun::vv2v::meta::inf + + namespace meta + { + + struct inf + { + + // A meta-fun can act as a function :-) + + template <typename T> + T operator()(const T& t1, const T& t2) const + // Here, we know the result type of vv2v::inf<T> so + // we explictly write it. + { + fun::vv2v::inf<T> f; + return f(t1, t2); + } + + // The "meta-fun -> fun" code is similar to the one in + // mln/accu/min.hh + template <typename T> + struct with + { + typedef fun::vv2v::inf<T> ret; + }; + }; + + } // mln::fun::vv2v::meta + + } // mln::fun::vv2v + + } // mln::fun + + + + // Yay! A special type equipped with a particular 'inf'. + + struct rgb : Value<rgb> + { + typedef rgb enc; + typedef rgb equiv; // Those couple of typedefs are required by the concept. + rgb() {} + rgb(int r, int g, int b) : r(r), g(g), b(b) {} + int r, g, b; + }; + + std::ostream& operator<<(std::ostream& ostr, const rgb& c) + { + ostr << c.r << ' ' << c.g << ' ' << c.b; + } + + namespace trait + { + + template <> + struct set_precise_unary_< fun::vv2v::inf, rgb > + { + typedef set_precise_unary_< fun::vv2v::inf, rgb > ret; + + static rgb exec(const rgb& c1, const rgb& c2) + { + // "Inf" is component-wise "min". + return rgb(c1.r < c2.r ? c1.r : c2.r, + c1.g < c2.g ? c1.g : c2.g, + c1.b < c2.b ? c1.b : c2.b); + } + }; + + } // mln::trait + +} // mln + + + +int main() +{ + using namespace mln; + + fun::vv2v::meta::inf inf; + std::cout << inf(3, 5) << std::endl; + + rgb c1(1, 2, 3), c2(2, 1, 2); + std::cout << inf(c1, c2) << std::endl; +}