Add comments to fwd_declare_component example

examples/c/entities/fwd_declare_component/src/main.c

@@ -6,7 +6,7 @@
 // component id, but this variable is scoped to the function only. When trying
 // to access the component from another function, this typically causes errors
 // that look like this:
-//   "FLECS__EComponentName" is undefined
+//   "FLECS_IDComponentNameID" is undefined
 //
 // Forward declaring a component will make the component id available from other
 // functions, which fixes this error.
@@ -17,9 +17,19 @@ typedef struct {
 } Position;
 
 // The forward declaration of the component id variable. This variable will have
-// the name FLECS__EPosition, to ensure its name won't conflict with the type.
+// the name FLECS_IDPositionID, to ensure its name won't conflict with the type.
 ECS_COMPONENT_DECLARE(Position);
 
+// When you want forward declare a component from a header, make sure to use the
+// extern keyword to prevent multiple definitions of the same variable:
+//
+// In the header:
+//   extern ECS_COMPONENT_DECLARE(Position);
+//
+// In *one* of the source files:
+//  ECS_COMPONENT_DECLARE(Position);
+
+
 // To forward declare entities created with ECS_ENTITY, ECS_TAG or ECS_PREFAB,
 // use ECS_DECLARE.
 ECS_DECLARE(Wizard);

examples/cpp/queries/find_entity/src/main.cpp

@@ -2,7 +2,7 @@
 #include <iostream>
 
 struct Position {
-    double x, y;
+    int x, y;
 };
 
 int main() {
@@ -16,7 +16,7 @@ int main() {
 
     // Find the entity for which Position.x is 20
     flecs::entity e = q.find([](Position& p) {
-        return p.x == 20.0;
+        return p.x == 20;
     });
 
     if (e) {