reflection/nested_struct

• C

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  #include <nested_struct.h>
  #include <stdio.h>
   
  typedef struct {
      float x, y;
  } Point;
   
  typedef struct {
      Point start, stop;
  } Line;
   
  int main(int argc, char *argv[]) {
      ecs_world_t *ecs = ecs_init_w_args(argc, argv);
   
      ECS_COMPONENT(ecs, Point);
      ECS_COMPONENT(ecs, Line);
   
      ecs_struct(ecs, {
          .entity = ecs_id(Point),
          .members = {
              { .name = "x", .type = ecs_id(ecs_f32_t) },
              { .name = "y", .type = ecs_id(ecs_f32_t) }
          }
      });
   
      ecs_struct(ecs, {
          .entity = ecs_id(Line),
          .members = {
              { .name = "start", .type = ecs_id(Point) },
              { .name = "stop", .type = ecs_id(Point) }
          }
      });
   
      ecs_entity_t ent = ecs_new(ecs);
      ecs_set(ecs, ent, Line, {{10, 20}, {30, 40}});
   
      const Line *ptr = ecs_get(ecs, ent, Line);
      char *str = ecs_ptr_to_expr(ecs, ecs_id(Line), ptr);
      printf("%s\n", str); // {start: {x: 10, y: 20}, stop: {x: 30, y: 40}}
      ecs_os_free(str);
   
      return ecs_fini(ecs);
  }

• C++

  View on GitHub

  #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 Line as usual
      flecs::entity e = ecs.entity()
          .set<Line>({{10, 20}, {30, 40}});
   
      // Convert Line component to flecs expression string
      const Line& l = e.get<Line>();
      std::cout << ecs.to_expr(&l).c_str() << std::endl;
      // {start: {x: 10.00, y: 20.00}, stop: {x: 30.00, y: 40.00}}
  }