Rejuvenating C++ Programs through Demacrofication Aditya Kumar Andrew Sutton Bjarne Stroustrup Computer Science Engineering Computer Science Engineering Computer Science Engineering Texas A&M University Texas A&M University Texas A&M University College Station,Texas-77840 College Station,Texas-77840 College Station,Texas-77840 Email:
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[email protected] Abstract—We describe how legacy C++ programs can be of the C preprocessor has been reduced. The use of general- rejuvenated using C++11 features such as generalized constant ized constant expressions, type deduction, perfect forwarding, expressions, perfect forwarding, and lambda expressions. In lambda expressions, and alias templates eliminate the need for general, this work develops a correspondence between different kinds of macros and the C++ declarations to which they should many previous preprocessor-based idioms and solutions. be transformed. We have created a set of demacrofication tools Older C++ programs can be rejuvenated by replacing error- to assist a developer in the rejuvenation of C++ programs. To prone uses of the C preprocessor with type safe C++11 evaluate the work, we have applied the rejuvenation tools to declarations. In this paper, we present methods and tools a number of C++ libraries to assess the extent to which these to support the task of demacrofying C++ programs during libraries might be improved by demacrofication. Results indicate that between 68 and 98% of potentially refactorable macros could rejuvenation. This task is intended to be completed with the be transformed into C++11 declarations. Additional experiments help of a programmer; it is not a fully automated process.