File.ExistsAsync missing from the async File methods.

[CryoMyst]

Why is this missing from the File methods?

Seems useful for networks shares or slow raid arrays on HDDs that have spun down.

[stephentoub]

How would you implement it?

[teo-tsirpanis]

Hello @CryoMyst, unfortunately there is no OS support for asynchronously checking whether a file exists. Perhaps it could be added on Linux with io_uring but exposing new platform-specific async I/O APIs is a discussion that would better come after io_uring itself.

[huoyaoyuan]

As you can see, there's no OpenAsync DeleteAsync etc either. Currently async filesystem (instead of async IO) is not supported for most platforms.