From d66f09f1348f9805149b9eab4940cb9c00742984 Mon Sep 17 00:00:00 2001
From: graehl <graehl@ec762483-ff6d-05da-a07a-a48fb63a330f>
Date: Wed, 21 Jul 2010 20:12:44 +0000
Subject: Score::Clone() via CRTP

git-svn-id: https://ws10smt.googlecode.com/svn/trunk@360 ec762483-ff6d-05da-a07a-a48fb63a330f
---
 vest/scorer.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'vest/scorer.h')

diff --git a/vest/scorer.h b/vest/scorer.h
index 0d90f378..0c8b380f 100644
--- a/vest/scorer.h
+++ b/vest/scorer.h
@@ -46,6 +46,18 @@ class Score : public boost::intrusive_refcount<Score> {
   virtual void Encode(std::string* out) const = 0;
   static ScoreP GetZero(ScoreType type);
   static ScoreP GetOne(ScoreType type);
+  virtual ScoreP Clone() const = 0;
+protected:
+  Score() {  } // we define these explicitly because refcount is noncopyable
+  Score(Score const& o) {  }
+};
+
+//TODO: make sure default copy ctors for score types do what we want.
+template <class Derived>
+struct ScoreBase : public Score {
+  ScoreP Clone() const  {
+    return ScoreP(new Derived(dynamic_cast<Derived const&>(*this)));
+  }
 };
 
 class SentenceScorer {
-- 
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