Int to String - manipulating string

[mickey]

Hello, I have to wirte this method and I'd like one efficent and compact:

int _low, _high;
std::string MyClass:: print() { 		
		std::string str;
		std::string result;
		std::stringstream ss; 
 
		result += "[";		
		ss << _low;
		ss >> str;
		result += str;
 
		result.append("-");
 
		ss << _high;
		ss >> str;
		result += str;
		result.append("]");		
		return result; 
	}
//main
MyClass mycl;
cout << " The range is: " << mycl.print() << endl

int _low, _high;
std::string MyClass:: print() { 		
		std::string str;
		std::string result;
		std::stringstream ss; 

		result += "[";		
		ss << _low;
		ss >> str;
		result += str;
		
		result.append("-");
		
		ss << _high;
		ss >> str;
		result += str;
		result.append("]");		
		return result; 
	}
//main
MyClass mycl;
cout << " The range is: " << mycl.print() << endl

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it must print: "the range is [10-20]"

It seems too large and not compact.... How can I improve?
Thanks.

[DeepDiver]

Implement an output stream operator for your class like this:

inline std::ostream& operator<<(std::ostream& os, const MyClass& c)
{ return os << "[" << c.low() << "-" << c.high() << "]"; }

inline std::ostream& operator<<(std::ostream& os, const MyClass& c)
{ return os << "[" << c.low() << "-" << c.high() << "]"; }

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In action:

MyClass mycl;
cout << " The range is: " << mycl << endl;

MyClass mycl;
cout << " The range is: " << mycl << endl;

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[mickey]

hello, thanks but I had an error like this:
error C2804: binary 'operator <<' has too many parameters

[wysota]

Did you implement it as a method of your class or as a standalone function? It should be the latter.

[mickey]

Did you implement it as a method of your class or as a standalone function? It should be the latter.

I had to declare it as friend method.....because my situation was it:

//subnode.cpp
class SubNode {
     protected:
               int _low, _high;
}
 
//node.cpp
class Node : SubNode {
   ........
   int other;
 
};
friend inline std::ostream& operator<<(std::ostream& os, const Node& n) { 
			return os << "[" << n._low << "-" << n._high << "]"; 
	} 		
//end node.cpp

//subnode.cpp
class SubNode {
     protected:
               int _low, _high;
}

//node.cpp
class Node : SubNode {
   ........
   int other;

};
friend inline std::ostream& operator<<(std::ostream& os, const Node& n) { 
			return os << "[" << n._low << "-" << n._high << "]"; 
	} 		
//end node.cpp

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If I declare the inline function in node.cpp but after class declaration ( after "};" ) it gets an error that it can't acces to protected member.
Is it ok in this way or I can be better?

[wysota]

It has to be a standalone function, not a method. If you want it to be a method of your class, you have to omit the second parameter (const Node& n).

[mickey]

Hi, I declared it as below. it seem works both them

//subnode.cpp
class SubNode {
     protected:
               int _low, _high;
}
 
//node.cpp
class Node : SubNode {
   ........
   int other;
friend std::ostream& operator<<(std::ostream& os, const Node& n) { 
			return os << "[" << n._low << "-" << n._high << "]"; 
	} 		
};
//inline std::ostream& operator<<(std::ostream& os, /*const*/ Node& n) { 
//			return os << "[" << n.GETLOW() << "-" << n.GETHIGH() << "]"; 
//	} 	
//end node.cpp

//subnode.cpp
class SubNode {
     protected:
               int _low, _high;
}

//node.cpp
class Node : SubNode {
   ........
   int other;
friend std::ostream& operator<<(std::ostream& os, const Node& n) { 
			return os << "[" << n._low << "-" << n._high << "]"; 
	} 		
};
//inline std::ostream& operator<<(std::ostream& os, /*const*/ Node& n) { 
//			return os << "[" << n.GETLOW() << "-" << n.GETHIGH() << "]"; 
//	} 	
//end node.cpp

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Out of class 'const' gets error; idem for _low and _high that I coudn't access them because they are protected....