Added cast operator

lib/coveo/linq/detail/linq_detail.h

@@ -324,6 +324,17 @@ class average_impl
     }
 };
 
+// Selector implementation used by cast operator.
+template<typename U>
+class cast_selector
+{
+public:
+    template<typename T>
+    auto operator()(T&& obj) const -> U {
+        return static_cast<U>(obj);
+    }
+};
+
 // Implementation of concat operator.
 template<typename Seq2>
 class concat_impl

lib/coveo/linq/linq.h

@@ -169,6 +169,19 @@ auto average(const F& num_f)
     return detail::average_impl<F>(num_f);
 }
 
+// C++ LINQ operator: cast
+// .NET equivalent: Cast
+
+// Operator that casts (using static_cast) the elements
+// in a sequence to a different type.
+template<typename U>
+auto cast()
+    -> detail::select_impl<detail::indexless_selector_proxy<detail::cast_selector<U>>>
+{
+    return detail::select_impl<detail::indexless_selector_proxy<detail::cast_selector<U>>>(
+        detail::indexless_selector_proxy<detail::cast_selector<U>>(detail::cast_selector<U>()));
+}
+
 // C++ LINQ operator: concat
 // .NET equivalent: Concat
 

tests/coveo/linq/linq_tests.cpp

@@ -217,6 +217,20 @@ void linq_tests()
                          | average([](int i) { return i; }));
     }
 
+    // cast
+    {
+        const std::vector<int> vi = { 42, 23, 66 };
+        const std::vector<double> vd = { 42.0, 23.0, 66.0 };
+
+        using namespace coveo::linq;
+        auto seq_d = from(vi)
+                   | cast<double>();
+        COVEO_ASSERT(detail::equal(std::begin(seq_d), std::end(seq_d),
+                                   std::begin(vd), std::end(vd)));
+        COVEO_ASSERT(seq_d.has_fast_size());
+        COVEO_ASSERT(seq_d.size() == vd.size());
+    }
+
     // concat
     {
         const std::vector<int> a = { 42, 23 };