Map/Set in .natvis files

[AlexEne]

I am going to open this issue here as this wg probably has most members using windows so I think this can be tracked by us for now until someone starts actual work on it.

.natvis files don't support map and set data structures and it would be a great addition if they did have a nice debug visualizer for them.

If someone from this wg wants to pick it up then that would be great, if not I am considering setting up a bounty for it.

[MaulingMonkey]

Some existing upstream issues for cross referencing:

• Investigate natvis for improved msvc debugging rust-lang/rust#36503
• Metaissue for Visual Studio debugging Rust rust-lang/rust#40460

[MaulingMonkey]

Existing stdlib natvis files - any new files dropped in here should be automatically picked up by rustc (EDIT: this is no longer true, see the linked PR for where to manually list natvis files so they get bundled!) and added to the pdbs of rust programs built using MSVC toolchains:

• https://github.com/rust-lang/rust/tree/master/src/etc/natvis
• %USERPROFILE%\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\etc
  If you want to hot reload your natvis files, don't initially add them here, instead add them to your VS project or use the VS Code launch.json setting.

To avoid regressions, I recommend adding unit tests to verify your .natvis files work after you've gotten them working. Example here for Vec and String:

• rust-lang/rust@e33c441#diff-fd8dc5085419aaef41a4e8383344ef15

To run those unit tests, aside from all the usual setup for contributing to rustc, you'll also want the debugging tools from the Windows SDK ( https://developer.microsoft.com/en-us/windows/downloads/windows-10-sdk ) or similar.