http://code.google.com/p/double-conversion This project (double-conversion) provides binary-decimal and decimal-binary routines for IEEE doubles. The library consists of efficient conversion routines that have been extracted from the V8 JavaScript engine. The code has been refactored and improved so that it can be used more easily in other projects. There is extensive documentation in src/double-conversion.h. Other examples can be found in test/cctest/test-conversions.cc.