[API Proposal]: Implement IUtf8SpanParsable on Guid

[SirCxyrtyx]

Background and motivation

As part of #81500 :

Implement IUtf8SpanParsable on Guid. Additionally, add a utf8 Parse and TryParse that do not take the unused IFormatProvider parameter. This matches how ISpanParsable was implemented.

Draft PR: #105654

API Proposal

namespace System;

public readonly partial struct Guid
    : ISpanFormattable,
      IComparable,
      IComparable<Guid>,
      IEquatable<Guid>,
      ISpanParsable<Guid>,
      IUtf8SpanFormattable,
+      IUtf8SpanParsable<Guid>
{
+    public static Guid Parse(ReadOnlySpan<byte> utf8Text);
+    public static bool TryParse(ReadOnlySpan<byte> utf8Text, out Guid result);

+    public static Guid Parse(ReadOnlySpan<byte> utf8Text, IFormatProvider? provider);
+    public static bool TryParse(ReadOnlySpan<byte> utf8Text, IFormatProvider? provider, out Guid result);
}

API Usage

var utf8GuidText = "{a8a110d5-fc49-43c5-bf46-802db8f843ff}"u8;

if (Guid.TryParse(utf8GuidText, out Guid guid))
{
    //do something with guid
}

Alternative Designs

No response

Risks

There are a few aspects to this that I am unsure about.

• Given that the IFormatProvider parameter is unused, I think IUtf8SpanParsable ought to be implemented explicitly. But that would not be consistent with the ISpanParsable implementation.
• Should a utf8 version of ParseExact and TryParseExact also be added for consistency?
• Guid has a constructor that takes a string, which is the same as calling Guid.Parse(string). It also has a constructor that takes a ReadOnlySpan<byte>, but this will not be equivalent to calling Guid.Parse(ReadOnlySpan<byte>), as that constructor deserializes from a binary representation of a Guid. Is this inconsistency a problem?

[tannergooding]

This is already approved by #81500, it just hasn't been implemented yet