Workaround a C++/CLI bug involving DIMs

src/libraries/System.Private.CoreLib/src/System/Numerics/INumberBase.cs

@@ -27,7 +27,7 @@ public interface INumberBase<TSelf>
           ISubtractionOperators<TSelf, TSelf, TSelf>,
           IUnaryPlusOperators<TSelf, TSelf>,
           IUnaryNegationOperators<TSelf, TSelf>,
-          IUtf8SpanFormattable,
+          // IUtf8SpanFormattable,
           IUtf8SpanParsable<TSelf>
         where TSelf : INumberBase<TSelf>?
     {
@@ -457,7 +457,9 @@ static virtual bool TryParse(ReadOnlySpan<byte> utf8Text, NumberStyles style, IF
             return succeeded;
         }
 
-        bool IUtf8SpanFormattable.TryFormat(Span<byte> utf8Destination, out int bytesWritten, ReadOnlySpan<char> format, IFormatProvider? provider)
+        // Workaround devdiv/#1851707: C++/CLI fails to compile when encountering a Default Interface Method implemented in a derived interface
+        // bool IUtf8SpanFormattable.TryFormat(Span<byte> utf8Destination, out int bytesWritten, ReadOnlySpan<char> format, IFormatProvider? provider)
+        bool TryFormat(Span<byte> utf8Destination, out int bytesWritten, ReadOnlySpan<char> format, IFormatProvider? provider)
         {
             char[]? utf16DestinationArray;
             scoped Span<char> utf16Destination;

src/libraries/System.Runtime/ref/System.Runtime.cs

@@ -10799,7 +10799,7 @@ public partial interface IMultiplyOperators<TSelf, TOther, TResult> where TSelf
         static virtual TResult operator checked *(TSelf left, TOther right) { throw null; }
         static abstract TResult operator *(TSelf left, TOther right);
     }
-    public partial interface INumberBase<TSelf> : System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf>, System.IUtf8SpanFormattable, System.IUtf8SpanParsable<TSelf> where TSelf : System.Numerics.INumberBase<TSelf>?
+    public partial interface INumberBase<TSelf> : System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf>, /* System.IUtf8SpanFormattable, */ System.IUtf8SpanParsable<TSelf> where TSelf : System.Numerics.INumberBase<TSelf>?
     {
         static abstract TSelf One { get; }
         static abstract int Radix { get; }
@@ -10841,7 +10841,9 @@ static virtual TSelf CreateTruncating<TOther>(TOther value)
         static virtual TSelf Parse(System.ReadOnlySpan<byte> utf8Text, System.Globalization.NumberStyles style, System.IFormatProvider? provider) { throw null; }
         static abstract TSelf Parse(System.ReadOnlySpan<char> s, System.Globalization.NumberStyles style, System.IFormatProvider? provider);
         static abstract TSelf Parse(string s, System.Globalization.NumberStyles style, System.IFormatProvider? provider);
-        bool System.IUtf8SpanFormattable.TryFormat(System.Span<byte> utf8Destination, out int bytesWritten, System.ReadOnlySpan<char> format, System.IFormatProvider? provider) { throw null; }
+        // Workaround devdiv/#1851707: C++/CLI fails to compile when encountering a Default Interface Method implemented in a derived interface
+        // bool System.IUtf8SpanFormattable.TryFormat(System.Span<byte> utf8Destination, out int bytesWritten, System.ReadOnlySpan<char> format, System.IFormatProvider? provider) { throw null; }
+        bool TryFormat(System.Span<byte> utf8Destination, out int bytesWritten, System.ReadOnlySpan<char> format, System.IFormatProvider? provider) { throw null; }
         static TSelf System.IUtf8SpanParsable<TSelf>.Parse(System.ReadOnlySpan<byte> utf8Text, System.IFormatProvider? provider) { throw null; }
         static bool System.IUtf8SpanParsable<TSelf>.TryParse(System.ReadOnlySpan<byte> utf8Text, System.IFormatProvider? provider, [System.Diagnostics.CodeAnalysis.MaybeNullWhen(false)] out TSelf result) { throw null; }
         protected static abstract bool TryConvertFromChecked<TOther>(TOther value, [System.Diagnostics.CodeAnalysis.MaybeNullWhen(false)] out TSelf result)
@@ -11320,7 +11322,7 @@ internal ConstructorInvoker() { }
         public object? Invoke(object? arg1, object? arg2, object? arg3) { throw null; }
         public object? Invoke(object? arg1, object? arg2, object? arg3, object? arg4) { throw null; }
         public static System.Reflection.ConstructorInvoker Create(System.Reflection.ConstructorInfo constructor) { throw null; }
-    }    
+    }
     public partial class CustomAttributeData
     {
         protected CustomAttributeData() { }