union shared ptrs to single instance if possible

alib2data/src/common/wrapper.hpp

@@ -18,6 +18,15 @@ class wrapper {
 protected:
 	std::cow_shared_ptr < T > data;
+private:
+
+	void unify(wrapper& other) {
+		if(this->data.getUseCount() > other.data.getUseCount()) {
+			other.data = this->data;
+		} else {
+			this->data = other.data;
+		}
+	}
 public:
 	explicit wrapper ( T * data ) : data ( data ) {
 	}
@@ -78,7 +87,9 @@ public:
 	int compare ( const wrapper & other ) const {
 		if ( this->data.get ( ) == other.data.get ( ) ) return 0;
-		return ( * this->data ).compare ( * other.data );
+		int res = ( * this->data ).compare ( * other.data );
+		if(res == 0) const_cast<wrapper*>(this)->unify(const_cast<wrapper&>(other));
+		return res;
 	}
 	friend std::ostream & operator <<( std::ostream & os, const wrapper & instance ) {

alib2std/src/extensions/memory.hpp

@@ -86,6 +86,11 @@ public:
 		return m_Data == NULL || m_Data->m_UseCount == 1;
 	}
+	int getUseCount() const {
+		if(m_Data == NULL) return 0;
+		return m_Data->m_UseCount;
+	}
+
 private:
 	void attach ( T * data ) {
 		m_Data = data;