stringstream

So I'm trying to read input like this from the standard input (using cin ): Adam English 85 Charlie Math 76 Erica History 82 Richard Science 90 My goal is to eventually store each data piece in its own cell in a data structure I have created, so basically I want to parse the input so each piece of data is individual. Since each row of input is inputted by the user one at a time, each time I get an entire row of input that I need to parse. Currently I am trying something like this: stringstream ss; getline(cin, ss); string name; string course; string grade; ss >> name >> course >> grade; The

I know one of the advantages of std::stringstream is that it is a std::istream so it may accept input from any type that defines operator<< to std::istream , and also from primitives types. I am not going to use operator<< ; instead I am just going to concatenate many strings. Does the implementation of std::stringstream make it faster than std::string for concatenating many strings? Nicol Bolas There's no reason to expect std::string 's appending functions to be slower than stringstream 's insertion functions. std::string will generally be nothing more than a possible memory allocation/copy

One of the possibilities is: somestringstream.str(""); But is it most optimal? Is there any way to preserve stringstream internal buffer, so that following operator<<() calls would not require to reserve memory again? Brian R. Bondy I've always done: s.clear();//clear any bits set s.str(std::string()); @litb gets into more detail about how to seekp to the start of the stream combined with std::ends you can keep your allocated size. 来源： https://stackoverflow.com/questions/834622/best-way-to-empty-stringstream

I want to output an integer to a std::stringstream with the equivalent format of printf 's %02d . Is there an easier way to achieve this than: std::stringstream stream; stream.setfill('0'); stream.setw(2); stream << value; Is it possible to stream some sort of format flags to the stringstream , something like (pseudocode): stream << flags("%02d") << value; You can use the standard manipulators from <iomanip> but there isn't a neat one that does both fill and width at once: stream << std::setfill('0') << std::setw(2) << value; It wouldn't be hard to write your own object that when inserted into

Why does this line give the error Error: incomplete type is not allowed ? stringstream ss; #include <sstream> and use the fully qualified name i.e. std::stringstream ss; Please, add: #include <sstream> An incomplete type is when the compiler knows the identifier is a type, for instance because you have a forward-declaration of it (e.g. class stringstream; ), but it hasn't seen a full definition for it ( class stringstream { ... }; ). This could happen for a type that is only present through included header files -- when you've included header files that use the type, but not the header file

With my recent upgrade to Mac OS X 10.9 the default standard C++ library changed from libstdc++ to libc++. Since then I observe unexpected behaviour of the stringstream operator>>(double) documented in the code example below. In summary the libc++ seems to have problems with extracting double values from stringstreams when the double value is followed by a letter. I already checked the standard (2003) but I can't find any specific information if extraction should work in this case or not. So I would be grateful for any input whether this is a bug in libc++ or libstdc++. #include <sstream>