handle - untested, first revision for an idea

handle.h

@@ -0,0 +1,57 @@
+#ifndef MAG_HANDLE_H
+#define MAG_HANDLE_H
+
+#ifdef __cplusplus
+#error "handle.h does not work with C++ compilers, you must compile these files with GCC directly!"
+#endif
+
+/** Tells your constructor/destructor handler function about the state */
+enum HANDLE_STATE {
+	HANDLE_CREAT,
+	HANDLE_DESTR,
+};
+
+/**
+ * This creates a "handle". Basically a struct with given constructor and destructor + RAII.
+ *
+ * Usage:
+ *
+ * struct Meaning {
+ * 		int a;
+ * 		int b;
+ * };
+ * // You can typedef if you want, change code accordingly!
+ *
+ * handle(struct Meaning) {
+ * 	if(state == HANDLE_CREAT) {
+ * 		this->a = *(int*) data;
+ * 		this->b = 2
+ * 	} else {
+ * 		printf("%d\n", this->a + this->b);
+ * 	}
+ * }
+ *
+ * // Now you can use a handle in your local scopes
+ * // Should print 42:
+ * int main() {
+ * 		int initializer = 40;
+ * 		creat(struct Data, d, &initializer);
+ * }
+ *
+ * Rem.: Unrelated trick, but you can typedef struct A A; // both typedef and forward declare
+ */
+
+#define creat(TNAME, VNAME, VINIT) \
+	[[gnu::always_inline]] inline void F(TNAME *v) { \
+		TNAME##_lifetime_handler(HANDLE_DESTR, v, NULL); \
+	} \
+	[[gnu::cleanup(F)]] TNAME VNAME; \
+	TNAME##_lifetime_handler(HANDLE_CREAT, VNAME, VINIT);
+
+#define handle(TNAME) \
+	static void [[gnu::always_inline]] inline TNAME##_lifetime_handler( \
+		HANDLE_STATE state, \
+		TNAME *this, \
+		void *data)
+
+#endif // MAG_HANDLE_H

handle_test.c

@@ -0,0 +1,4 @@
+#include <stdio.h>
+
+int main() {
+}

innerf.c

@@ -5,12 +5,13 @@ int main() {
 	int b = 40;
 	int c = 2;
 
+	// See: https://gcc.gnu.org/onlinedocs/gcc-4.3.0/gcc/Nested-Functions.html
 	inline void lf(register int* r) {
 		a += *r;
 	}; // semicolon(;) not needeed!
 
 	/*
-	// Same as above...
+	// Same as above... but need auto storage class if you pre-declare
 	inline auto void lf(register int* r);
 	inline void lf(register int* r) {
 		a += *r;

makefile

@@ -7,6 +7,7 @@ gcc:
 	gcc construct_destruct.c -o construct_destruct
 	gcc raii_test.c -o raii_test
 	g++ raii_test.cpp -o raii_test_cpp
+	gcc handle_test.c -o handle_test
 clang:
 	clang macroname.c -o macroname
 	clang count.c -o count