now using cml for vectors and math stuff

[chaz/yoink] / src / cml / core / meta / switch.h

diff --git a/src/cml/core/meta/switch.h b/src/cml/core/meta/switch.h
new file mode 100644 (file)
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+++ b/src/cml/core/meta/switch.h
@@ -0,0 +1,173 @@
+/* -*- C++ -*- ------------------------------------------------------------
+ 
+Copyright (c) 2007 Jesse Anders and Demian Nave http://cmldev.net/
+
+The Configurable Math Library (CML) is distributed under the terms of the
+Boost Software License, v1.0 (see cml/LICENSE for details).
+
+ *-----------------------------------------------------------------------*/
+/** @file
+ *  @brief
+ */
+
+#ifndef meta_switch_h
+#define meta_switch_h
+
+#include <cml/core/meta/common.h>
+#include <cml/core/meta/if.h>
+
+namespace cml {
+
+struct NilCase {};      /* For terminating the case list. */
+struct Default {};      /* For indicating the default result. */
+
+/* The working parts of the meta-switch go into namespace meta: */
+namespace meta {
+
+/* "Interior" case statements: */
+template<typename Case, typename Result, typename NextCase>
+struct select_case
+{
+    template<typename Find> struct match {
+        typedef typename select_if<
+            same_type<Find,Case>::is_true,
+            Result,
+            typename NextCase::template match<Find>::result
+        >::result result;
+    };
+};
+
+/* Default case, returned when no match is found in a previous case: */
+template<typename Result>
+struct select_case<Default,Result,NilCase>
+{
+    template<typename Find> struct match {
+        typedef Result result;
+    };
+};
+
+/* The last case statement (if no match until now, the result is 'void'): */
+template<typename Case, typename Result>
+struct select_case<Case,Result,NilCase>
+{
+    template<typename Find> struct match {
+        typedef typename select_if<
+            same_type<Find,Case>::is_true,
+            Result,
+            void
+        >::result result;
+    };
+};
+
+} // namespace meta
+
+/** Return the matched type (like a switch/case statement).
+ *
+ * This is a convenience wrapper to avoid having to explicitly type out
+ * select_case for each case in the list of types to match against.
+ */
+template<typename Find
+, typename T1,           typename R1
+, typename T2 = NilCase, typename R2 = void
+, typename T3 = NilCase, typename R3 = void
+, typename T4 = NilCase, typename R4 = void
+, typename T5 = NilCase, typename R5 = void
+, typename T6 = NilCase, typename R6 = void
+, typename T7 = NilCase, typename R7 = void
+, typename T8 = NilCase, typename R8 = void
+, typename T9 = NilCase, typename R9 = void
+, typename T10 = NilCase, typename R10 = void
+, typename T11 = NilCase, typename R11 = void
+, typename T12 = NilCase, typename R12 = void
+, typename T13 = NilCase, typename R13 = void
+, typename T14 = NilCase, typename R14 = void
+, typename T15 = NilCase, typename R15 = void
+, typename T16 = NilCase, typename R16 = void
+#if !defined(_MSC_VER)
+, typename T17 = NilCase, typename R17 = void
+, typename T18 = NilCase, typename R18 = void
+, typename T19 = NilCase, typename R19 = void
+, typename T20 = NilCase, typename R20 = void
+, typename T21 = NilCase, typename R21 = void
+, typename T22 = NilCase, typename R22 = void
+, typename T23 = NilCase, typename R23 = void
+, typename T24 = NilCase, typename R24 = void
+, typename T25 = NilCase, typename R25 = void
+, typename T26 = NilCase, typename R26 = void
+, typename T27 = NilCase, typename R27 = void
+, typename T28 = NilCase, typename R28 = void
+, typename T29 = NilCase, typename R29 = void
+, typename T30 = NilCase, typename R30 = void
+, typename T31 = NilCase, typename R31 = void
+, typename T32 = NilCase, typename R32 = void
+, typename T33 = NilCase, typename R33 = void
+, typename T34 = NilCase, typename R34 = void
+, typename T35 = NilCase, typename R35 = void
+, typename T36 = NilCase, typename R36 = void
+, typename T37 = NilCase, typename R37 = void
+, typename T38 = NilCase, typename R38 = void
+, typename T39 = NilCase, typename R39 = void
+, typename T40 = NilCase, typename R40 = void
+#endif
+> struct select_switch
+{
+    typedef typename
+          meta::select_case< T1,R1
+        , meta::select_case< T2,R2
+        , meta::select_case< T3,R3
+        , meta::select_case< T4,R4
+        , meta::select_case< T5,R5
+        , meta::select_case< T6,R6
+        , meta::select_case< T7,R7
+        , meta::select_case< T8,R8
+        , meta::select_case< T9,R9
+        , meta::select_case< T10,R10
+        , meta::select_case< T11,R11
+        , meta::select_case< T12,R12
+        , meta::select_case< T13,R13
+        , meta::select_case< T14,R14
+        , meta::select_case< T15,R15
+        , meta::select_case< T16,R16
+#if !defined(_MSC_VER)
+        , meta::select_case< T17,R17
+        , meta::select_case< T18,R18
+        , meta::select_case< T19,R19
+        , meta::select_case< T20,R20
+        , meta::select_case< T21,R21
+        , meta::select_case< T22,R22
+        , meta::select_case< T23,R23
+        , meta::select_case< T24,R24
+        , meta::select_case< T25,R25
+        , meta::select_case< T26,R26
+        , meta::select_case< T27,R27
+        , meta::select_case< T28,R28
+        , meta::select_case< T29,R29
+        , meta::select_case< T30,R30
+        , meta::select_case< T31,R31
+        , meta::select_case< T32,R32
+        , meta::select_case< T33,R33
+        , meta::select_case< T34,R34
+        , meta::select_case< T35,R35
+        , meta::select_case< T36,R36
+        , meta::select_case< T37,R37
+        , meta::select_case< T38,R38
+        , meta::select_case< T39,R39
+        , meta::select_case< T40,R40
+        , NilCase
+        > > > > > > > > > >     /* 10 */
+        > > > > > > > > > >     /* 10 */
+        > > > >    /* 4 */
+#else
+        , NilCase
+#endif
+        > > > > > >     /* 6 */
+        > > > > > > > > > >     /* 10 */
+        ::template match<Find>::result result;
+};
+
+} // namespace cml
+
+#endif
+
+// -------------------------------------------------------------------------
+// vim:ft=cpp