now using cml for vectors and math stuff

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

diff --git a/src/cml/core/meta/common.h b/src/cml/core/meta/common.h
new file mode 100644 (file)
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+++ b/src/cml/core/meta/common.h
@@ -0,0 +1,88 @@
+/* -*- 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 core_meta_common_h
+#define core_meta_common_h
+
+namespace cml {
+
+/** Type of a true statement. */
+struct true_type {};
+
+/** Type of a false statement. */
+struct false_type {};
+
+template<bool B> struct is_true {
+    typedef false_type result;
+};
+
+template<> struct is_true<true> {
+    typedef true_type result;
+};
+
+/** A "type pair". */
+template<typename T1, typename T2> struct type_pair {
+    typedef T1 first;
+    typedef T2 second;
+};
+
+/** A "type quadruple". */
+template<typename T1, typename T2, typename T3, typename T4>
+struct type_quad {
+    typedef T1 first;
+    typedef T2 second;
+    typedef T3 third;
+    typedef T3 fourth;
+};
+
+/** Match any type (for use with same_type<> and select_switch<>). */
+struct any_type {};
+
+/** Determine if two types are the same.
+ *
+ * Defaults to false.
+ */
+template<typename T, typename U> struct same_type {
+    typedef false_type result;
+    enum { is_true = false, is_false = true };
+};
+
+/** Match the same type for both of same_type's template arguments. */
+template<typename T> struct same_type<T,T> {
+    typedef true_type result;
+    enum { is_true = true, is_false = false };
+};
+
+/** Match a type and any_type. */
+template<typename T> struct same_type<T,any_type> {
+    typedef true_type result;
+    enum { is_true = true, is_false = false };
+};
+
+/** Match a type and any_type. */
+template<typename T> struct same_type<any_type,T> {
+    typedef true_type result;
+    enum { is_true = true, is_false = false };
+};
+
+/** Disambiguate pair of any_type's. */
+template<> struct same_type<any_type,any_type> {
+    typedef true_type result;
+    enum { is_true = true, is_false = false };
+};
+
+} // namespace cml
+
+#endif
+
+// -------------------------------------------------------------------------
+// vim:ft=cpp