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#include <cstdlib>
#include <functional>
#include <iostream>
#include <type_traits>
#include <typeinfo>
#include <utility>
#include <vector>
#include <mapbox/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(";
bool first = true;
for (auto const& pt : line)
{
if (!first) std::cerr << ",";
std::cerr << pt.x << " " << pt.y;
if (first) first = false;
}
std::cerr << ")" << std::endl;
}
template <typename T>
void operator()(T const& val) const
{
std::cerr << typeid(T).name() << std::endl;
}
};
}
int main()
{
std::cerr << sizeof(test::polygon) << std::endl;
std::cerr << sizeof(test::variant) << std::endl;
test::point pt(123, 456);
test::variant var = 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::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;
}
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