1 files changed, 47 insertions, 0 deletions
diff --git a/geom_bottleneck/include/dnn/utils.h b/geom_bottleneck/include/dnn/utils.h
new file mode 100644
index 0000000..f4ce632
--- /dev/null
+++ b/geom_bottleneck/include/dnn/utils.h
@@ -0,0 +1,47 @@
+#ifndef HERA_BT_DNN_UTILS_H
+#define HERA_BT_DNN_UTILS_H
+
+#include <boost/random/uniform_int.hpp>
+#include <boost/foreach.hpp>
+#include <boost/typeof/typeof.hpp>
+
+namespace hera
+{
+namespace bt
+{
+namespace dnn
+{
+
+template <typename T, typename... Args>
+struct has_coordinates
+{
+    template <typename C, typename = decltype( std::declval<C>().coordinate(std::declval<Args>()...) )>
+    static std::true_type test(int);
+
+    template <typename C>
+    static std::false_type test(...);
+
+    static constexpr bool value = decltype(test<T>(0))::value;
+};
+
+template<class RandomIt, class UniformRandomNumberGenerator, class SwapFunctor>
+void random_shuffle(RandomIt first, RandomIt last, UniformRandomNumberGenerator& g, const SwapFunctor& swap)
+{
+    size_t n = last - first;
+    boost::uniform_int<size_t> uniform(0,n);
+    for (size_t i = n-1; i > 0; --i)
+        swap(first[i], first[uniform(g,i+1)]);      // picks a random number in [0,i] range
+}
+
+template<class RandomIt, class UniformRandomNumberGenerator>
+void random_shuffle(RandomIt first, RandomIt last, UniformRandomNumberGenerator& g)
+{
+    typedef     decltype(*first)            T;
+    random_shuffle(first, last, g, [](T& x, T& y) { std::swap(x,y); });
+}
+
+} // dnn
+} // bt
+} // hera
+
+#endif