System.Text.Utf8.Utf8Encoder.TryEncodeCodePoint C# (CSharp) Method

        public static bool TryEncodeCodePoint(UnicodeCodePoint codePoint, Span<byte> buffer, out int encodedBytes)
        {
            if (!UnicodeCodePoint.IsSupportedCodePoint(codePoint))
            {
                encodedBytes = 0;
                return false;
            }

            encodedBytes = GetNumberOfEncodedBytes(codePoint);
            if (encodedBytes > buffer.Length)
            {
                encodedBytes = 0;
                return false;
            }

            switch (encodedBytes)
            {
                case 1:
                    buffer[0] = (byte)(b0111_1111U & codePoint.Value);
                    return true;
                case 2:
                    byte b0 = (byte)(((codePoint.Value >> 6) & b0001_1111U) | b1100_0000U);
                    byte b1 = (byte)(((codePoint.Value >> 0) & b0011_1111U) | b1000_0000U);
                    buffer.Write((ushort)(b0 | b1 << 8));
                    return true;
                case 3:
                    b0 = (byte)(((codePoint.Value >> 12) & b0000_1111U) | b1110_0000U);
                    b1 = (byte)(((codePoint.Value >> 6) & b0011_1111U) | b1000_0000U);
                    buffer.Write((ushort)(b0 | b1 << 8));
                    buffer[2] = (byte)(((codePoint.Value >> 0) & b0011_1111U) | b1000_0000U);
                    return true;
                case 4:
                    b0 = (byte)(((codePoint.Value >> 18) & b0000_0111U) | b1111_0000U);
                    b1 = (byte)(((codePoint.Value >> 12) & b0011_1111U) | b1000_0000U);
                    byte b2 = (byte)(((codePoint.Value >> 6) & b0011_1111U) | b1000_0000U);
                    byte b3 = (byte)(((codePoint.Value >> 0) & b0011_1111U) | b1000_0000U);
                    buffer.Write((uint)(b0 | b1 << 8 | b2 << 16 | b3 << 24));
                    return true;
                default:
                    return false;
            }
        }
        #endregion

        public unsafe Utf8EncodedCodePoint(char highSurrogate, char lowSurrogate) : this()
        {
            UnicodeCodePoint codePoint = (UnicodeCodePoint)(uint)char.ConvertToUtf32(highSurrogate, lowSurrogate);

            fixed(byte *encodedData = &_byte0)
            {
                Span <byte> buffer = new Span <byte>(encodedData, 4);

                if (!Utf8Encoder.TryEncodeCodePoint(codePoint, buffer, out _length))
                {
                    // TODO: Change exception type
                    throw new Exception("Internal error: this should never happen as codePoint should be within acceptable range");
                }
            }
        }