New example for constructor usage!

examples/source/usertype.constructors.cpp

@@ -0,0 +1,50 @@
+#define SOL_ALL_SAFETIES_ON 1
+#include <sol/sol.hpp>
+
+#include <string>
+#include <iostream>
+
+class MyClass {
+public:
+	MyClass(double d) : data(d) {}
+	double data;
+};
+
+int main() {
+	std::cout << "=== coroutine ===" << std::endl;
+
+
+	sol::state lua;
+	lua.open_libraries(sol::lib::base);
+
+	lua.new_usertype<MyClass>("MyClass",
+		sol::meta_function::construct, sol::factories(
+			// MyClass.new(...) -- dot syntax, no "self" value passed in
+			[](const double& d) {return std::make_shared<MyClass>(d);},
+			// MyClass:new(...) -- colon syntax, passes in the "self" value
+			// as first argument implicitly
+			[](sol::object, const double& d) {return std::make_shared<MyClass>(d);}
+		),
+		// MyClass(...) syntax, only
+		sol::call_constructor, sol::factories([](const double& d) {return std::make_shared<MyClass>(d);}),
+		"data", &MyClass::data
+	);
+
+	sol::optional<sol::error> maybe_error = lua.safe_script(R"(
+		d1 = MyClass(2.1)
+		d2 = MyClass:new(3.1)
+		d3 = MyClass(4.1)
+		assert(d1.data == 2.1)
+		assert(d2.data == 2.1)
+		assert(d3.data == 2.1)
+	)", sol::script_pass_on_error);
+
+	if (maybe_error) {
+		// something went wrong!
+		std::cerr << "Something has gone horribly unexpected and wrong:\n" << maybe_error->what() << std::endl;
+		return 1;
+	}
+
+	// everything is okay!
+	return 0;
+}