Buffer: not copyable, add destructor

src/buffer.cc

@@ -29,6 +29,12 @@ Buffer::Buffer(const std::string& name, Type type,
     compute_lines();
 }
 
+Buffer::~Buffer()
+{
+    m_windows.clear();
+    assert(m_modification_listeners.empty());
+}
+
 void Buffer::erase(const BufferIterator& begin, const BufferIterator& end)
 {
     append_modification(BufferModification(BufferModification::Erase,

src/buffer.hh

@@ -104,6 +104,10 @@ public:
 
     Buffer(const std::string& name, Type type,
            const BufferString& initial_content = "");
+    Buffer(const Buffer&) = delete;
+    Buffer(Buffer&&) = delete;
+    Buffer& operator= (const Buffer&) = delete;
+    ~Buffer();
 
     void           begin_undo_group();
     void           end_undo_group();