Improved docs/ex. Fix range bug when container is empty cvec/cdeq.

1 files changed, 9 insertions, 2 deletions

diff --git a/examples/music_arc.c b/examples/music_arc.c
index 02470b0f..6f9c1c72 100644
--- a/examples/music_arc.c
+++ b/examples/music_arc.c
@@ -19,12 +19,14 @@ void Song_drop(Song* s) {
     c_drop(cstr, &s->artist, &s->title);
 }
 
+// Define the reference counted type
 #define i_type SongArc
 #define i_val Song
 #define i_valdrop Song_drop
 #define i_cmp Song_cmp
 #include <stc/carc.h>
 
+// ... and a vector of it
 #define i_type SongVec
 #define i_val_arcbox SongArc
 #include <stc/cvec.h>
@@ -39,13 +41,18 @@ void example3()
             Song_from("Thalia", "Entre El Mar y Una Estrella")
         }) SongVec_emplace(&vec, *v);
 
+        // Share all entries in vec with vec2, except Bob Dylan.
         c_foreach (s, SongVec, vec)
             if (!cstr_equals(&s.ref->get->artist, "Bob Dylan"))
-                SongVec_push_back(&vec2, SongArc_clone(*s.ref));
+                SongVec_push(&vec2, SongArc_clone(*s.ref));
 
+        // Add a few more to vec2. We can use emplace when creating new entries
         SongVec_emplace(&vec2, Song_from("Michael Jackson", "Billie Jean"));
         SongVec_emplace(&vec2, Song_from("Rihanna", "Stay"));
+        // If we use push, we would need to construct the Arc explicitly (as in c++, make_shared):
+        // SongVec_push(&vec2, SongArc_from(Song_from("Rihanna", "Stay")));
 
+        // We now have two vectors with some shared, some unique entries.
         c_forarray (SongVec, v, {vec, vec2}) {
             puts("VEC:");
             c_foreach (s, SongVec, *v)
@@ -53,7 +60,7 @@ void example3()
                                                  cstr_str(&s.ref->get->title),
                                                  *s.ref->use_count);
         }
-    }
+    } // because the shared elem. are ref. counted, they are only dropped once here.
 }
 
 int main()