winforms - which library is used for StreamWriter in C++ window forms? -

public ref class form : public system::windows::forms::form { public:      form(void)     {         initializecomponent();         void save(string^ word);      }     //windows form generated code     ...     ...     ...     void save(string^ word)     {         streamwriter^ outfile = gcnew streamwriter("file.txt");         outfile->writeline(word);         outfile->close();     }     #pragma endregion  private:      system::void button00_click(system::object^  sender, system::eventargs^  e)     {         string^ word = "plow";         save(word);     } }; } 

streamwriter resides in namespace system::io , implemented in mscorlib.dll. add line

using namespace system::io

to imports of code file , ready go.