1 files changed, 173 insertions, 0 deletions
diff --git a/libbackend-elements/backend-elements/indentation/clip.hxx b/libbackend-elements/backend-elements/indentation/clip.hxx
new file mode 100644
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+++ b/libbackend-elements/backend-elements/indentation/clip.hxx
@@ -0,0 +1,173 @@
+// file      : backend-elements/indentation/clip.hxx
+// author    : Boris Kolpackov <boris@kolpackov.net>
+// copyright : Copyright (c) 2005-2010 Boris Kolpackov
+// license   : GNU GPL v2 + exceptions; see accompanying LICENSE file
+
+#ifndef BACKEND_ELEMENTS_INDENTATION_CLIP_HXX
+#define BACKEND_ELEMENTS_INDENTATION_CLIP_HXX
+
+#include <backend-elements/types.hxx>
+
+#include <backend-elements/indentation/buffer.hxx>
+
+#include <ostream>
+
+namespace BackendElements
+{
+  namespace Indentation
+  {
+    template <typename C>
+    class ToStreambufAdapter: public std::basic_streambuf<C>,
+                              public NonCopyable
+    {
+    public:
+      typedef
+      typename std::basic_streambuf<C>::traits_type
+      Traits;
+
+      typedef
+      typename std::basic_streambuf<C>::char_type
+      AsChar;
+
+      typedef
+      typename std::basic_streambuf<C>::int_type
+      AsInt;
+
+    public:
+      ToStreambufAdapter (Buffer<C>& buffer)
+          : buffer_ (buffer)
+      {
+      }
+
+      virtual AsInt
+      overflow (AsInt ch)
+      {
+        return buffer_.put (Traits::to_char_type (ch));
+      }
+
+      virtual Int
+      sync ()
+      {
+        return 0;
+      }
+
+    private:
+      Buffer<C>& buffer_;
+    };
+
+
+    template <typename C>
+    class FromStreambufAdapter: public Buffer<C>
+    {
+    public:
+      typedef
+      typename Buffer<C>::Traits
+      Traits;
+
+      typedef
+      typename Buffer<C>::AsChar
+      AsChar;
+
+      typedef
+      typename Buffer<C>::AsInt
+      AsInt;
+
+      typedef
+      typename Buffer<C>::Write
+      Write;
+
+    public:
+      FromStreambufAdapter (std::basic_streambuf<C>& b)
+          : buffer_ (b)
+      {
+      }
+
+      virtual AsInt
+      put (AsChar ch)
+      {
+        return buffer_.sputc (ch);
+      }
+
+      virtual Void
+      unbuffer ()
+      {
+        try
+        {
+          if (buffer_.pubsync () == 0) return;
+        }
+        catch (std::ios_base::failure const&)
+        {
+        }
+
+        throw Write ();
+      }
+
+    private:
+      std::basic_streambuf<C>& buffer_;
+    };
+
+
+    template <template <typename> class Buffer, typename C = Char>
+    class Clip: public NonCopyable
+    {
+    public:
+      Clip (std::basic_ostream<C>& os)
+          : os_ (os),
+            prev_ (os_.rdbuf ()),
+            from_adapter_ (*prev_),
+            buffer_ (from_adapter_),
+            to_adapter_ (buffer_)
+      {
+        os_.rdbuf (&to_adapter_);
+      }
+
+      /*
+      template <typename Arg0>
+      Clip (std::basic_ostream<C>& os, Arg0 a0)
+          : os_ (os),
+            prev_ (os_.rdbuf ()),
+            from_adapter_ (*prev_),
+            buffer_ (from_adapter_, a0),
+            to_adapter_ (buffer_)
+      {
+        os_.rdbuf (&to_adapter_);
+      }
+      */
+
+      ~Clip ()
+      {
+        try
+        {
+          buffer_.unbuffer ();
+        }
+        catch (...)
+        {
+          os_.rdbuf (prev_);
+          throw;
+        }
+
+        os_.rdbuf (prev_);
+      }
+
+      Buffer<C>&
+      buffer ()
+      {
+        return buffer_;
+      }
+
+    private:
+      std::basic_ostream<C>& os_;
+      std::basic_streambuf<C>* prev_;
+
+      FromStreambufAdapter<C> from_adapter_;
+
+      Buffer<C> buffer_;
+
+      ToStreambufAdapter<C> to_adapter_;
+    };
+  }
+}
+
+#include <backend-elements/indentation/clip.txx>
+
+#endif  // BACKEND_ELEMENTS_INDENTATION_CLIP_HXX