Imported Upstream version 4.0.0upstream/4.0.0

1 files changed, 71 insertions, 0 deletions

diff --git a/libcutl/cutl/container/key.hxx b/libcutl/cutl/container/key.hxx
new file mode 100644
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+++ b/libcutl/cutl/container/key.hxx
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+// file      : cutl/container/key.hxx
+// copyright : Copyright (c) 2009-2013 Code Synthesis Tools CC
+// license   : MIT; see accompkeying LICENSE file
+
+#ifndef CUTL_CONTAINER_KEY_HXX
+#define CUTL_CONTAINER_KEY_HXX
+
+namespace cutl
+{
+  namespace container
+  {
+    // A modifiable map key wrapper that can be used to implement multi-
+    // index containers, as discussed in the following post:
+    //
+    // http://www.codesynthesis.com/~boris/blog/2012/09/11/emulating-boost-multi-index-with-std-containers/
+    //
+    template <class T1, class T2 = void, class T3 = void>
+    struct key;
+
+    template <class T1>
+    struct key<T1, void, void>
+    {
+      mutable const T1* p1;
+
+      key (): p1 (0) {}
+      key (const T1& r1): p1 (&r1) {}
+      void assign (const T1& r1) const {p1 = &r1;}
+
+      bool operator< (const key& x) const {return *p1 < *x.p1;}
+    };
+
+    template <class T1, class T2>
+    struct key<T1, T2, void>
+    {
+      mutable const T1* p1;
+      mutable const T2* p2;
+
+      key (): p1 (0), p2 (0) {}
+      key (const T1& r1, const T2& r2): p1 (&r1), p2 (&r2) {}
+      void assign (const T1& r1, const T2& r2) const {p1 = &r1; p2 = &r2;}
+
+      bool operator< (const key& x) const
+      {
+        return *p1 < *x.p1 || (!(*x.p1 < *p1) && *p2 < *x.p2);
+      }
+    };
+
+    template <class T1, class T2, class T3>
+    struct key
+    {
+      mutable const T1* p1;
+      mutable const T2* p2;
+      mutable const T3* p3;
+
+      key (): p1 (0), p2 (0), p3 (0) {}
+      key (const T1& r1, const T2& r2, const T3& r3)
+          : p1 (&r1), p2 (&r2) , p3 (&r3) {}
+      void assign (const T1& r1, const T2& r2, const T3& r3) const
+      {p1 = &r1; p2 = &r2; p3 = &r3;}
+
+      bool operator< (const key& x) const
+      {
+        return (*p1 < *x.p1 ||
+                (!(*x.p1 < *p1) && (*p2 < *x.p2 ||
+                                    (!(*x.p2 < *p2) && *p3 < *x.p3))));
+      }
+    };
+  }
+}
+
+#endif // CUTL_CONTAINER_KEY_HXX