version 3

src/cppmap.h

@@ -0,0 +1,44 @@
+/* Copyright 2015. The Regents of the University of California.
+ * All rights reserved. Use of this source code is governed by
+ * a BSD-style license which can be found in the LICENSE file.
+ *
+ * Authors:
+ * 2015 Martin Uecker <martin.uecker@med.uni-goettingen.de>
+ */
+
+
+// some classic C preprocessor hackery
+
+/* Ideas from:
+ *
+ * https://github.com/swansontec/map-macro
+ * https://github.com/pfultz2/Cloak/wiki/Is-the-C-preprocessor-Turing-complete%3F
+ */
+
+#define EMPTY()
+#define DEFER1(...) __VA_ARGS__ EMPTY()
+#define DEFER2(...) __VA_ARGS__ DEFER1(EMPTY)()
+#define DEFER3(...) __VA_ARGS__ DEFER2(EMPTY)()
+
+#define EXPAND6(...) __VA_ARGS__
+#define EXPAND5(...) EXPAND6(EXPAND6(__VA_ARGS__))
+#define EXPAND4(...) EXPAND5(EXPAND5(__VA_ARGS__))
+#define EXPAND3(...) EXPAND4(EXPAND4(__VA_ARGS__))
+#define EXPAND2(...) EXPAND3(EXPAND3(__VA_ARGS__))
+#define EXPAND1(...) EXPAND2(EXPAND2(__VA_ARGS__))
+#define EXPAND0(...) EXPAND1(EXPAND1(__VA_ARGS__))
+#define EXPAND(...) EXPAND0(EXPAND0(__VA_ARGS__))
+
+#define CAT0(x, y) x ## y
+#define CAT(x, y) CAT0(x, y)
+#define NIL_TEST() DUMMY, TRUE,
+#define RET2ND0(a, b, ...) b
+#define RET2ND(...) RET2ND0(__VA_ARGS__)
+#define NIL_P(x) RET2ND(NIL_TEST x, FALSE)
+#define IF_TRUE(a, b) a
+#define IF_FALSE(a, b) b
+#define IF(x, a, b) CAT(IF_, x)(a, b)
+#define MAP1() MAP0
+#define MAP0(f, arg, a, b, ...) f(arg, a) IF(NIL_P(b), , DEFER3(MAP1)()(f, arg, b, __VA_ARGS__))
+#define MAP(f, arg, ...) EXPAND(MAP0(f, arg, __VA_ARGS__, ()))
+

src/namespace.h

@@ -1,4 +1,5 @@
 
+#include "cppmap.h"
 
 #define NAMESPACE_PREFIX(ns, x) ns ## _ ## x
 #define NAMESPACE_ENTRY(ns, x) typeof(NAMESPACE_PREFIX(ns, x)) *x;
@@ -10,3 +11,9 @@ static const struct \
 
 #define NAMESPACE(S) (const struct { S(S, NAMESPACE_ENTRY) }){ S(S, NAMESPACE_INIT) }
 
+
+// version 2
+
+#define namespace(S, ...) \
+static const struct { MAP(NAMESPACE_ENTRY, S, __VA_ARGS__) } S = { MAP(NAMESPACE_INIT, S, __VA_ARGS__) }
+