Add Path.TryGetTempPath()

[JeremyKuhne]

From API proposal #25173.

Need to add:

namespace System.IO
{
    public static class Path
    {
        public static bool TryGetTempPath(Span<char> destination, out int charsWritten);
    }
}

Returns false if the destination isn't large enough to fit the full path into.

[MarcoRossignoli]

@JeremyKuhne if you want i can start with this, feel free to assign to me

[jkotas]

@JeremyKuhne Do we have examples of where the no-allocation version of this API makes a difference?

You are about to create a temporary file. Creating a temporary file is orders of magnitude more expensive operation than just allocating a string.

I think the no-allocation version of these APIs are adding negative value to the platform.

[jkotas]

(Add Path.TryGetRelativePath() and Path.TryGetFullPath() are fine.)

[JeremyKuhne]

Video

Closing for now until we re-review the API proposal.