Add UUIDv4 generator

src/uuid/uuid.h

@@ -0,0 +1,34 @@
+#ifndef UUID_H
+#define UUID_H
+
+#include "../common/aliases/aliases.h"
+#include "../core/strings/str8/str8.h"
+
+#ifdef __cplusplus
+BEGIN_C_LINKAGE
+#endif // __cplusplus
+
+#define UUID_BUF_LENGTH 48
+#define WAPP_UUID_SPEC WAPP_STR8_SPEC
+#define wapp_uuid_varg(UUID) wapp_str8_varg((UUID).uuid)
+
+typedef struct uuid UUID;
+struct uuid {
+  Str8 uuid;
+};
+
+#define wapp_uuid_gen_uuid4() *(wapp_uuid_init_uuid4(&wapp_uuid_create()))
+
+/* Low level UUID API */
+
+#define wapp_uuid_create() ((UUID){.uuid = wapp_str8_buf(UUID_BUF_LENGTH)})
+
+// Just returns the same pointer that was passed in with the UUID initialised.
+// If the pointer is NULL, it skips initialisation.
+UUID *wapp_uuid_init_uuid4(UUID *uuid);
+
+#ifdef __cplusplus
+END_C_LINKAGE
+#endif // __cplusplus
+
+#endif // !UUID_H