JsonCpp Files

This release is based on branch 00.11.z, which is different from branch 0.y.z and 1.y.z.

The main purpose of this release is to give users a third choice, that is, users can only have a copy of the code, but can build in different environments, so it can be used with old or newer compilers.

The benefit is that users can use some new features in this new branch that introduced in 1.y.z, but can hardly applied into 0.y.z.

All changes in the source code are for compatibility with pre-C++11 and C++11 standards. At the same time , we add more CIs to ensure all changes in all environments can work well.