cleanup: small refactor and comments

* Use MIT instead of GPL to be able to use at work.
* Don't use anonymous structures, actually declare a struct type.
* Expand comments a bit.

1 files changed, 22 insertions, 9 deletions

diff --git a/optional.h b/optional.h
index 3916898..30576f5 100644
--- a/optional.h
+++ b/optional.h
@@ -1,10 +1,18 @@
-/* SPDX-License-Identifier: GPL-2.0 */
+/* SPDX-License-Identifier: MIT */
 /**
  * optional.h - Macros for optional types
  *
  * Copyright (C) 2023 Yaroslav de la Peña Smirnov
  *
- * Poor man's optional "type templates" for C
+ * Documentation
+ * =============
+ *
+ * Poor man's optional "type templates" for C.
+ *
+ * An object of optional type is an object that may or may not hold an object of
+ * a certain type inside itself at any time. Before declaring a variable of a
+ * certain OPTIONAL type, said OPTIONAL type should be declared with the
+ * OPTIONALDEC macro.
  */
 
 #ifndef OPTIONAL_H
@@ -13,11 +21,16 @@
 #include <stdbool.h>
 
 /**
+ * OPTIONALDEC - declare OPTIONAL type that holds data of type @T
+ * @T:		the type of data to hold.
+ */
+#define OPTIONALDEC(T) struct __OPTIONAL_##T { bool has; T data; }
+
+/**
  * OPTIONAL - declare an object that optionally holds type @T
  * @T:		the type of data to hold.
- * @name:	the name of the variable or struct field.
  */
-#define OPTIONAL(T, name) struct { bool has; T data; } name
+#define OPTIONAL(T) struct __OPTIONAL_##T
 
 /**
  * OPTNONE - initialize an OPTIONAL object to hold nothing.
@@ -42,19 +55,19 @@
  * @d:		data to hold.
  */
 #define opt_set_some(opt, d) \
-	(opt.has = true, opt.data = d)
+	((opt).has = true, (opt).data = d)
 
 /**
  * opt_has - true if an OPTIONAL object has something.
  * @opt:	OPTIONAL object.
  */
-#define opt_has(opt) (opt.has)
+#define opt_has(opt) ((opt).has)
 
 /**
  * opt_hasnt - true if an OPTIONAL object has nothing.
  * @opt:	OPTIONAL object.
  */
-#define opt_hasnt(opt) (!opt.has)
+#define opt_hasnt(opt) (!(opt).has)
 
 /**
  * opt_unwrap - if there's something in @src, copy it to @dst.
@@ -64,13 +77,13 @@
  * Returns true if there was something, false if there wasn't.
  */
 #define opt_unwrap(src, dst) \
-	(opt_has(src) ? (dst = src.data, true) : (false))
+	(opt_has(src) ? (dst = (src).data, true) : (false))
 
 /**
  * opt_default - get something from @src or default to @def.
  * @src:	OPTIONAL object to get data from.
  * @def:	default value if there's nothing.
  */
-#define opt_default(src, def) opt_has(src) ? src.data : def
+#define opt_default(src, def) opt_has(src) ? (src).data : def
 
 #endif