In recent discussions it sounds like the filesystem structure of the source code is likely to change on dev following the transition to cmake. This includes potentially removing the distinction between core/ and src/, though that isn't the focus here.

@daljit46 mentioned a preference for having cpp/ at the root directory, in distinction to the current python/ root directory.

In mucking around with the content relating to testing, it occurred to me that there we have "binaries" and "scripts" appearing, both in the filesystem structure and in the invocation of specific tests. It may well be the case that adopting the "cpp" vs "python" distinction here would make things more consistent.