System.Text.BinHexEncoding.GetChars C# (CSharp) Method

        unsafe public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex)
        {
            if (bytes == null)
                throw new ArgumentNullException(nameof(bytes));
            if (byteIndex < 0)
                throw new ArgumentOutOfRangeException(nameof(byteIndex), SR.ValueMustBeNonNegative);
            if (byteIndex > bytes.Length)
                throw new ArgumentOutOfRangeException(nameof(byteIndex), SR.Format(SR.OffsetExceedsBufferSize, bytes.Length));
            if (byteCount < 0)
                throw new ArgumentOutOfRangeException(nameof(byteCount), SR.ValueMustBeNonNegative);
            if (byteCount > bytes.Length - byteIndex)
                throw new ArgumentOutOfRangeException(nameof(byteCount), SR.Format(SR.SizeExceedsRemainingBufferSpace, bytes.Length - byteIndex));
            int charCount = GetCharCount(bytes, byteIndex, byteCount);
            if (chars == null)
                throw new ArgumentNullException(nameof(chars));
            if (charIndex < 0)
                throw new ArgumentOutOfRangeException(nameof(charIndex), SR.ValueMustBeNonNegative);
            if (charIndex > chars.Length)
                throw new ArgumentOutOfRangeException(nameof(charIndex), SR.Format(SR.OffsetExceedsBufferSize, chars.Length));
            if (charCount < 0 || charCount > chars.Length - charIndex)
                throw new ArgumentException(SR.XmlArrayTooSmall, nameof(chars));
            if (byteCount > 0)
            {
                fixed (char* _val2char = s_val2char)
                {
                    fixed (byte* _bytes = &bytes[byteIndex])
                    {
                        fixed (char* _chars = &chars[charIndex])
                        {
                            char* pch = _chars;
                            byte* pb = _bytes;
                            byte* pbMax = _bytes + byteCount;
                            while (pb < pbMax)
                            {
                                pch[0] = _val2char[pb[0] >> 4];
                                pch[1] = _val2char[pb[0] & 0x0F];
                                pb++;
                                pch += 2;
                            }
                        }
                    }
                }
            }
            return charCount;
        }
    }