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Language: C++
Expertise: Intermediate

Mar 5, 2001

In pre-standard C++, certain implementations of <fstream.h> 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 <fstream> library, which supersedes the deprecated, pre-standard <fstream.h> 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(