In pre-standard C++, certain implementations of offered the flags ios::nocreate and ios::noreplace for controlling file creation. These flags were too platform-specific and never made it into the standard library, which supersedes the deprecated, pre-standard header. However, you can achieve the functionality of these obsolete flags rather easily. The following example imitates the ios::nocreate flag. First, it attempts to open a file for read. If the file doesn’t exist, no new file is created. If the file exists, the program closes it and reopens it in write mode:

 fstream fs(