Properly link flecs library

engine/libs/flecs/examples/cpp/reflection/nested_struct/src/main.cpp

@@ -0,0 +1,34 @@
+#include <nested_struct.h>
+#include <iostream>
+
+struct Point {
+    float x;
+    float y;
+};
+
+struct Line {
+    Point start;
+    Point stop;
+};
+
+int main(int, char *[]) {
+    flecs::world ecs;
+
+    // Register components with reflection data
+    ecs.component<Point>()
+        .member<float>("x")
+        .member<float>("y");
+
+    ecs.component<Line>()
+        .member<Point>("start")
+        .member<Point>("stop");
+
+    // Create entity with Position as usual
+    flecs::entity e = ecs.entity()
+        .set<Line>({{10, 20}, {30, 40}});
+
+    // Convert position component to flecs expression string
+    const Line *ptr = e.get<Line>();
+    std::cout << ecs.to_expr(ptr).c_str() << std::endl;
+    // {start: {x: 10.00, y: 20.00}, stop: {x: 30.00, y: 40.00}}
+}