I recently had to work with a very large codebase, in which each and every file included a header file with the statement “using namespace
std;” in it.
This led to the situation that hundreds of header files, using std strings, pairs, etc, were using those items without any std:: dereferencing.
Cleaning this situation up by hand would have taken weeks and been error prone, so I wrote a little script to do it for me, and called it standardize.pl
The variable possible_offenders is a list of std c++ names which are frequently in place in the code in question.
The script recursively searches a directory for for .h and .cpp files. For cpp files, it checks if any of the possible_offenders occur in the file. If so, it adds a “using namespace standard” directive if none exists. Thus cpp files are changed minimally.
For header files, all occurences of “using namespace std” are removed, and all occurences of possible_offenders are prefaced by an explicit std:: namespace specification. Care is taken not to change occurences in comments or in quotations.
If you are faced with a similar situation, you can find the script on github: https://github.com/spacemoose/standardize