ostringstream

I've been using the Boost serialization library, which is actually pretty nice, and lets me make simple wrappers to save my serializable objects to strings, like so: namespace bar = boost::archive; namespace bio = boost::iostreams; template <class T> inline std::string saveString(const T & o) { std::ostringstream oss; bar::binary_oarchive oa(oss); oa << o; return oss.str(); } template <class T> inline void saveFile(const T & o, const char* fname) { std::ofstream ofs(fname, std::ios::out|std::ios::binary|std::ios::trunc); bar::binary_oarchive oa(ofs); oa << o; } template <class T> inline void

I'm trying to use std::ostringstream to convert a number into a string (char *), but it doesn't seem to be working. Here's the code I have: #include <windows.h> #include <sstream> int main() { std::ostringstream out; out << 1234; const char *intString = out.str().c_str(); MessageBox(NULL, intString, intString, MB_OK|MB_ICONEXCLAMATION); return 0; } The resulting message box simply has no text in it. This leads me to believe that the call to out.str().c_str() is returning an invalid string, but I'm not sure. Since I've trimmed this program down so far an am still getting the problem, I must

If I construct a string made of a list of space separated floating point values using std::ostringstream : std::ostringstream ss; unsigned int s = floatData.size(); for(unsigned int i=0;i<s;i++) { ss << floatData[i] << " "; } Then I get the result in a std::string : std::string textValues(ss.str()); However, this will cause an unnecessary deep copy of the string contents, as ss will not be used anymore. Is there any way to construct the string without copying the entire content? std::ostringstream offers no public interface to access its in-memory buffer unless it non-portably supports

When would I use std::istringstream , std::ostringstream and std::stringstream and why shouldn't I just use std::stringstream in every scenario (are there any runtime performance issues?). Lastly, is there anything bad about this (instead of using a stream at all): std::string stHehe("Hello "); stHehe += "stackoverflow.com"; stHehe += "!"; CB Bailey Personally, I find it very rare that I want to perform streaming into and out of the same string stream. Usually I want to either initialize a stream from a string and then parse it; or stream things to a string stream and then extract the result

I'm trying to write a macro that would allow me to do something like: FORMAT(a << "b" << c << d) , and the result would be a string -- the same as creating an ostringstream, inserting a...d , and returning .str() . Something like: string f(){ ostringstream o; o << a << "b" << c << d; return o.str() } Essentially, FORMAT(a << "b" << c << d) == f() . First, I tried: 1: #define FORMAT(items) \ ((std::ostringstream&)(std::ostringstream() << items)).str() If the very first item is a C string ( const char * ), it will print the address of the string in hex, and the next items will print fine. If the