CML1 Versions Save

New in CML 2.1:

• The test suite has been updated to use Catch.
• Dependency on the Boost libraries has been eliminated.
• The supported compilers list has been expanded.

Update to correct a VS2017 compilation error in some functions using a numeric_traits value to initialize a default "tolerance" argument.

Minor release to simplify Boost.UnitTestFramework integration, and to implement two useful type generators.

This is a minor release of CML2 to implement a new type_map metaprogram.