The Style Guide currently says to avoid use of the C++ Standard Library. It goes on to list a very limited number of exceptions.

There are a number of Standard Library facilities that have been discussed as being of interest and potentially usable. At least some of these meet many or all of the criteria one might think are required for HotSpot use, such as not using the standard global allocator and not requiring exceptions for core functionality.

It would be better if the Style Guide instead provided guidance on how to decide what Standard Library components we might choose to permit, and how to use them, instead of just saying no, don't use.

In particular, the Style Guide currently contains a "TODO" suggesting the introduction of wrapper headers for Standard Library headers containing permitted components. That should be promoted from a TODO to instead describe how we do things, and then follow through with existing usage.