Update cmap_api.md

1 files changed, 72 insertions, 1 deletions

diff --git a/docs/cmap_api.md b/docs/cmap_api.md
index 0ef6441f..cad0887a 100644
--- a/docs/cmap_api.md
+++ b/docs/cmap_api.md
@@ -167,7 +167,7 @@ The HEX of color BLACK is:[#000000]
 ```
 
 ### Example 2
-This example uses a cmap with cstr_t as mapped value, by the `using_cmap_strval(id, int)` macro.
+This example uses a cmap with cstr as mapped value, by the `using_cmap_strval(id, int)` macro.
 ```c
 #include "stc/cstr.h"
 #include "stc/cmap.h"
@@ -203,3 +203,74 @@ Output:
 110: White
 120: #cc7744ff
 ```
+
+### Example 3
+Demonstrate cmap with plain-old-data struct key type Vec3f: cmap<Vec3f, int>:
+```c
+#include "stc/cmap.h"
+#include <stdio.h>
+
+typedef struct { float x, y, z; } Vec3f;
+
+using_cmap(v3, Vec3f, int, c_default_del,
+                           c_default_clone,
+                           c_mem_equals,
+                           c_default_hash32);
+
+int main()
+{
+    cmap_v3 vecs = cmap_v3_init();
+
+    cmap_v3_put(&vecs, (Vec3f){1.0f, 0.0f, 0.0f}, 1);
+    cmap_v3_put(&vecs, (Vec3f){0.0f, 1.0f, 0.0f}, 2);
+    cmap_v3_put(&vecs, (Vec3f){0.0f, 0.0f, 1.0f}, 3);
+    cmap_v3_put(&vecs, (Vec3f){1.0f, 1.0f, 1.0f}, 4);
+
+    c_foreach (i, cmap_v3, vecs)
+        printf("{%f %f %f}: %d\n", i.ref->first.x,  i.ref->first.y,  i.ref->first.z,  i.ref->second);
+    puts("");
+
+    cmap_v3_del(&vecs);
+}
+```
+Output:
+```c
+{1.000000 1.000000 1.000000}: 4
+{1.000000 0.000000 0.000000}: 1
+{0.000000 1.000000 0.000000}: 2
+{0.000000 0.000000 1.000000}: 3
+```
+
+### Example 4
+Inverse: demonstrate cmap with mapped POD type Vec3f: cmap<int, Vec3f>:
+```c
+#include "stc/cmap.h"
+#include <stdio.h>
+
+typedef struct { float x, y, z; } Vec3f;
+
+using_cmap(iv, int, Vec3f);
+
+int main()
+{
+    cmap_iv vecs = cmap_iv_init();
+
+    cmap_iv_put(&vecs, 1, (Vec3f){1.0f, 0.0f, 0.0f});
+    cmap_iv_put(&vecs, 2, (Vec3f){0.0f, 1.0f, 0.0f});
+    cmap_iv_put(&vecs, 3, (Vec3f){0.0f, 0.0f, 1.0f});
+    cmap_iv_put(&vecs, 4, (Vec3f){1.0f, 1.0f, 1.0f});
+
+    c_foreach (i, cmap_iv, vecs)
+        printf("%d: {%f %f %f}\n", i.ref->first, i.ref->second.x,  i.ref->second.y,  i.ref->second.z);
+    puts("");
+
+    cmap_iv_del(&vecs);
+}
+```
+Output:
+```c
+4: {1.000000 1.000000 1.000000}
+3: {0.000000 0.000000 1.000000}
+2: {0.000000 1.000000 0.000000}
+1: {1.000000 0.000000 0.000000}
+``````