Properly link flecs library

engine/libs/flecs/examples/cpp/entities/emplace/src/main.cpp

@@ -0,0 +1,28 @@
+#include <emplace.h>
+#include <iostream>
+
+// The emplace method constructs a component directly in the storage vs. a 
+// regular set, which moves the value into an already constructed value in the
+// storage. This reduces the overhead of creating a new component.
+//
+// Components that do not have a default constructor need to be created with
+// emplace, as they can't be constructed automatically by flecs.
+
+struct NoDefaultCtor {
+    NoDefaultCtor(double x_, double y_) : x(x_), y(y_) { }
+
+    double x, y;
+};
+
+int main(int, char *[]) {
+    flecs::world ecs;
+
+    flecs::entity e = ecs.entity()
+        .emplace<NoDefaultCtor>(10.0, 20.0);
+
+    const NoDefaultCtor *ptr = e.get<NoDefaultCtor>();
+    std::cout << "{" << ptr->x << ", " << ptr->y << "}" << "\n";
+
+    // Output
+    //  {10, 20}
+}