Edit Question - KnowledgeHub

Title Body

Tonight I've been taking a look at some code I've been working on over the last few days, and began reading up on move semantics, specifically std::move. I have a few questions to ask you pros to ensure that I am going down the right path and not making any stupid assumptions! Firstly: 1) Originally, my code had a function that returned a large vector: template<class T> class MyObject { public: std::vector<T> doSomething() const; { std::vector<T> theVector; // produce/work with a vector right here return(theVector); }; // eo doSomething }; // eo class MyObject Given "theVector" is temporary in this and "throw-away", I modified the function to: std::vector<T>&& doSomething() const; { std::vector<T> theVector; // produce/work with a vector right here return(static_cast<std::vector<T>&&>(theVector)); }; // eo doSomething Is this correct? Any pitfalls in doing it this way? 2) I noticed in a function I have that returns std::string that it automatically called the move constructor. Debugging in to Return of the String (thankyou, Aragorn), I noticed it called an explicit move constructor. Why is there one for the string class and not vector? I didn't have to make any modifications to this function to take advantage of move semantics: // below, no need for std::string&& return value? std::string AnyConverter::toString(const boost::any& _val) const { string ret; // convert here return(ret); // No need for static_cast<std::string&&> ? }; // eo toString 3) Finally, I wanted to do some performance tests, is the amazingly-fast results I got because of std::move semantics or did my compiler (VS2010) do some optimizin

Tags (comma-separated) Cancel