pull latest mapbox/variant changes in

2015-04-13 15:37:43 +02:00
parent 6c5015811e e985c9714b
commit 27c9230a82
3 changed files with 131 additions and 0 deletions
@@ -0,0 +1,74 @@
+#include <iostream>
+#include <vector>
+#include <thread>
+#include <string>
+#include <sstream>
+#include <utility>
+#include <type_traits>
+#include <boost/timer/timer.hpp>
+#include "variant.hpp"
+
+using namespace mapbox;
+
+namespace test {
+
+struct point
+{
+public:
+    point (double x_, double y_)
+        : x(x_), y(y_) {}
+    double x;
+    double y;
+};
+
+struct line_string : std::vector<point> {};
+struct polygon : std::vector<line_string> {};
+using variant = util::variant<std::reference_wrapper<const point>,
+                              std::reference_wrapper<const line_string>,
+                              std::reference_wrapper<const polygon>>;
+
+struct print
+{
+    using result_type = void;
+    void operator() (point const& pt) const
+    {
+        std::cerr << "Point(" << pt.x << "," << pt.y << ")" << std::endl;
+    }
+    void operator() (line_string const& line) const
+    {
+        std::cerr << "Line(";
+        for (auto const& pt : line)
+        {
+            std::cerr << pt.x << " " << pt.y << ",";
+        }
+        std::cerr << ")" << std::endl;
+    }
+    template <typename T>
+    void operator() (T const& val) const
+    {
+        std::cerr << typeid(T).name() << std::endl;
+    }
+};
+
+
+}
+
+int main (int argc, char** argv)
+{
+    std::cerr << sizeof(test::polygon) << std::endl;
+    std::cerr << sizeof(test::variant) << std::endl;
+    test::point pt(123,456);
+    test::variant var = std::move(std::cref(pt));
+    util::apply_visitor(test::print(), var);
+    test::line_string line;
+    line.push_back(pt);
+    line.push_back(pt);
+    line.push_back(test::point(999,333));
+    var = std::move(std::cref(line));
+    util::apply_visitor(test::print(), var);
+    std::cerr << "Is line (cref) ? " << var.is<std::reference_wrapper<test::line_string const>>() << std::endl;
+    auto const& line2 = var.get<test::line_string>(); // accessing underlying type of std::reference_wrapper<T>
+    test::print printer;
+    printer(line2);
+    return EXIT_SUCCESS;
+}