osrm-backend/third_party/variant/test/reference_wrapper_test.cpp
2015-04-13 15:37:43 +02:00

75 lines
1.9 KiB
C++

#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;
}