The C++ standard library for Monza is based on libc++ with a custom subsetting focussed around in-memory operations.
It includes a new build option to remove support for fstream.
In addition, the existing options to disable filesystem and stdin support are also enabled.
The external threading support is used to implement support for certain thread-related functionality needed by Project Verona.
Be mindful that while std::mutex and std::condition_variable are available, using them can result in unexpected interation with the Verona-base concurrency.
Their usage should be avoided, unless the user understands the implications.
In practice, the header-based nature of the C++ standard library makes it difficult to reason about support as unused functions are never linked to detect missing dependencies from the C standard library. As such we cannot make easy claims about the available level of support.
In order to support C++ language features, Monza uses libcxxrt as the library underneath the standard library, which implements features such as exceptions and RTTI. Monza supports all the functionality available in libcxxrt.