--- /dev/null
+/* -*- 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