Add MemoryExtensions.TryWriteUtf8

src/libraries/System.Memory/ref/System.Memory.cs

@@ -382,6 +382,8 @@ public static void Sort<TKey, TValue, TComparer>(this System.Span<TKey> keys, Sy
         public static bool TryWrite<TArg0, TArg1, TArg2>(this System.Span<char> destination, System.IFormatProvider? provider, System.Text.CompositeFormat format, out int charsWritten, TArg0 arg0, TArg1 arg1, TArg2 arg2) { throw null; }
         public static bool TryWrite(this Span<char> destination, System.IFormatProvider? provider, System.Text.CompositeFormat format, out int charsWritten, params object?[] args) { throw null; }
         public static bool TryWrite(this Span<char> destination, System.IFormatProvider? provider, System.Text.CompositeFormat format, out int charsWritten, System.ReadOnlySpan<object?> args) { throw null; }
+        public static bool TryWriteUtf8(this System.Span<byte> destination, [System.Runtime.CompilerServices.InterpolatedStringHandlerArgumentAttribute("destination")] ref System.MemoryExtensions.TryWriteUtf8InterpolatedStringHandler handler, out int bytesWritten) { throw null; }
+        public static bool TryWriteUtf8(this System.Span<byte> destination, IFormatProvider? provider, [System.Runtime.CompilerServices.InterpolatedStringHandlerArgumentAttribute("destination", "provider")] ref System.MemoryExtensions.TryWriteUtf8InterpolatedStringHandler handler, out int bytesWritten) { throw null; }
         [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)]
         [System.Runtime.CompilerServices.InterpolatedStringHandlerAttribute]
         public ref struct TryWriteInterpolatedStringHandler
@@ -401,6 +403,27 @@ public ref struct TryWriteInterpolatedStringHandler
             public bool AppendFormatted(string? value) { throw null; }
             public bool AppendFormatted(string? value, int alignment = 0, string? format = null) { throw null; }
         }
+        [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)]
+        [System.Runtime.CompilerServices.InterpolatedStringHandlerAttribute]
+        public ref struct TryWriteUtf8InterpolatedStringHandler
+        {
+            private readonly object _dummy;
+            private readonly int _dummyPrimitive;
+            public TryWriteUtf8InterpolatedStringHandler(int literalLength, int formattedCount, System.Span<byte> destination, out bool shouldAppend) { throw null; }
+            public TryWriteUtf8InterpolatedStringHandler(int literalLength, int formattedCount, System.Span<byte> destination, IFormatProvider? provider, out bool shouldAppend) { throw null; }
+            public bool AppendLiteral(string value) { throw null; }
+            public bool AppendFormatted(scoped System.ReadOnlySpan<char> value) { throw null; }
+            public bool AppendFormatted(scoped System.ReadOnlySpan<char> value, int alignment = 0, string? format = null) { throw null; }
+            public bool AppendFormatted(scoped System.ReadOnlySpan<byte> utf8Value) { throw null; }
+            public bool AppendFormatted(scoped System.ReadOnlySpan<byte> utf8Value, int alignment = 0, string? format = null) { throw null; }
+            public bool AppendFormatted<T>(T value) { throw null; }
+            public bool AppendFormatted<T>(T value, string? format) { throw null; }
+            public bool AppendFormatted<T>(T value, int alignment) { throw null; }
+            public bool AppendFormatted<T>(T value, int alignment, string? format) { throw null; }
+            public bool AppendFormatted(object? value, int alignment = 0, string? format = null) { throw null; }
+            public bool AppendFormatted(string? value) { throw null; }
+            public bool AppendFormatted(string? value, int alignment = 0, string? format = null) { throw null; }
+        }
     }
 }
 namespace System.Buffers

src/libraries/System.Memory/tests/Span/TryWrite.cs

@@ -529,7 +529,7 @@ private static void AssertModeMatchesType<T>(T tss) where T : IHasToStringState
             Assert.Equal(expected, tss.ToStringState.ToStringMode);
         }
 
-        private sealed class SpanFormattableStringWrapper : IFormattable, ISpanFormattable, IHasToStringState
+        internal sealed class SpanFormattableStringWrapper : IFormattable, ISpanFormattable, IHasToStringState
         {
             private readonly string _value;
             public ToStringState ToStringState { get; } = new ToStringState();
@@ -576,7 +576,7 @@ public override string ToString()
             }
         }
 
-        private struct SpanFormattableInt32Wrapper : IFormattable, ISpanFormattable, IHasToStringState
+        internal struct SpanFormattableInt32Wrapper : IFormattable, ISpanFormattable, IHasToStringState
         {
             private readonly int _value;
             public ToStringState ToStringState { get; }
@@ -613,7 +613,7 @@ public override string ToString()
             }
         }
 
-        private sealed class FormattableStringWrapper : IFormattable, IHasToStringState
+        internal sealed class FormattableStringWrapper : IFormattable, IHasToStringState
         {
             private readonly string _value;
             public ToStringState ToStringState { get; } = new ToStringState();
@@ -637,7 +637,7 @@ public override string ToString()
             }
         }
 
-        private struct FormattableInt32Wrapper : IFormattable, IHasToStringState
+        internal struct FormattableInt32Wrapper : IFormattable, IHasToStringState
         {
             private readonly int _value;
             public ToStringState ToStringState { get; }
@@ -665,27 +665,27 @@ public override string ToString()
             }
         }
 
-        private sealed class ToStringState
+        internal sealed class ToStringState
         {
             public string LastFormat { get; set; }
             public IFormatProvider LastProvider { get; set; }
             public ToStringMode ToStringMode { get; set; }
         }
 
-        private interface IHasToStringState
+        internal interface IHasToStringState
         {
             ToStringState ToStringState { get; }
         }
 
-        private enum ToStringMode
+        internal enum ToStringMode
         {
             ObjectToString,
             IFormattableToString,
             ISpanFormattableTryFormat,
             ICustomFormatterFormat,
         }
 
-        private sealed class StringWrapper
+        internal sealed class StringWrapper
         {
             private readonly string _value;
 
@@ -694,7 +694,7 @@ private sealed class StringWrapper
             public override string ToString() => _value;
         }
 
-        private sealed class ConcatFormatter : IFormatProvider, ICustomFormatter
+        internal sealed class ConcatFormatter : IFormatProvider, ICustomFormatter
         {
             public object GetFormat(Type formatType) => formatType == typeof(ICustomFormatter) ? this : null;
 
@@ -714,7 +714,7 @@ public string Format(string format, object arg, IFormatProvider formatProvider)
             }
         }
 
-        private sealed class ConstFormatter : IFormatProvider, ICustomFormatter
+        internal sealed class ConstFormatter : IFormatProvider, ICustomFormatter
         {
             private readonly string _value;