Added virtual destructor, to silence a few more GCC 4 warnings

svn-id: r18419

3 files changed, 7 insertions, 0 deletions

diff --git a/common/stream.h b/common/stream.h
index b9b64bbfd7..c7890e5bdb 100644
--- a/common/stream.h
+++ b/common/stream.h
@@ -35,6 +35,8 @@ class String;
  */
 class Stream {
 public:
+	virtual ~Stream() {}
+
 	/**
 	 * Returns true if any I/O failure occured.
 	 * This flag is never cleared automatically. In order to clear it,
diff --git a/graphics/font.h b/graphics/font.h
index 230ae94c2b..6799d6769e 100644
--- a/graphics/font.h
+++ b/graphics/font.h
@@ -40,6 +40,9 @@ enum TextAlignment {
  */
 class Font {
 public:
+	Font() {}
+	virtual ~Font() {}
+
 	virtual int getFontHeight() const = 0;
 	virtual int getMaxCharWidth() const = 0;
 
diff --git a/gui/object.h b/gui/object.h
index 3ca5248228..5e81d5bb01 100644
--- a/gui/object.h
+++ b/gui/object.h
@@ -29,6 +29,7 @@ class CommandSender;
 class CommandReceiver {
 	friend class CommandSender;
 protected:
+	virtual ~CommandReceiver() {}
 	virtual void handleCommand(CommandSender *sender, uint32 cmd, uint32 data) {}
 };
 
@@ -39,6 +40,7 @@ protected:
 	CommandReceiver	*_target;
 public:
 	CommandSender(CommandReceiver *target) : _target(target) {}
+	virtual ~CommandSender() {}
 
 	void setTarget(CommandReceiver *target)	{ _target = target; }
 	CommandReceiver *getTarget() const		{ return _target; }