1 files changed, 67 insertions, 0 deletions
diff --git a/misc/examples/smartpointers/music_arc.c b/misc/examples/smartpointers/music_arc.c
new file mode 100644
index 00000000..13d368c3
--- /dev/null
+++ b/misc/examples/smartpointers/music_arc.c
@@ -0,0 +1,67 @@
+// shared_ptr-examples.cpp
+// based on https://docs.microsoft.com/en-us/cpp/cpp/how-to-create-and-use-shared-ptr-instances?view=msvc-160
+#define i_implement
+#include <stc/cstr.h>
+
+typedef struct
+{
+    cstr artist;
+    cstr title;
+} Song;
+
+int Song_cmp(const Song* x, const Song* y)
+    { return cstr_cmp(&x->title, &y->title); }
+
+Song Song_init(const char* artist, const char* title)
+    { return c_LITERAL(Song){cstr_from(artist), cstr_from(title)}; }
+
+void Song_drop(Song* s) {
+    printf("drop: %s\n", cstr_str(&s->title));
+    c_drop(cstr, &s->artist, &s->title);
+}
+
+// Define the shared pointer:
+#define i_type SongArc
+#define i_keyclass Song
+#define i_no_hash          // no hash fn for Song, fallback hash pointer to Song.
+#include <stc/carc.h>
+
+// ... and a vector of them
+#define i_type SongVec
+#define i_keyboxed SongArc // use i_keyboxed on carc / cbox (instead of i_key)
+#include <stc/cvec.h>
+
+void example3(void)
+{
+    SongVec vec1 = c_init(SongVec, {
+        Song_init("Bob Dylan", "The Times They Are A Changing"),
+        Song_init("Aretha Franklin", "Bridge Over Troubled Water"),
+        Song_init("Thalia", "Entre El Mar y Una Estrella")
+    });
+
+    SongVec vec2 = {0};
+    // Share all entries in vec with vec2, except Bob Dylan.
+    c_foreach (s, SongVec, vec1)
+        if (!cstr_equals(&s.ref->get->artist, "Bob Dylan"))
+            SongVec_push(&vec2, SongArc_clone(*s.ref));
+
+    // Add a few more to vec2. We can use emplace when creating new entries
+    // Emplace calls SongArc_from() on the argument to create the Arc:
+    SongVec_emplace(&vec2, Song_init("Michael Jackson", "Billie Jean"));
+    SongVec_emplace(&vec2, Song_init("Rihanna", "Stay"));
+
+    // We now have two vectors with some shared, some unique entries.
+    c_forlist (i, SongVec, {vec1, vec2}) {
+        puts("VEC:");
+        c_foreach (s, SongVec, *i.ref)
+            printf("  %s - %s, REFS: %ld\n", cstr_str(&s.ref->get->artist),
+                                             cstr_str(&s.ref->get->title),
+                                             *s.ref->use_count);
+    }
+    c_drop(SongVec, &vec1, &vec2);
+}
+
+int main(void)
+{
+    example3();
+}