System.Xml.Base64Decoder.Decode C# (CSharp) Method

        internal override unsafe int Decode( string str, int startPos, int len ) {
            Debug.Assert( str != null );
            Debug.Assert( len >= 0 );
            Debug.Assert( startPos >= 0 );
            Debug.Assert( str.Length - startPos >= len );

            if ( len == 0 ) {
                return 0;
            }
            int bytesDecoded, charsDecoded;
            fixed ( char* pChars = str ) {
                fixed ( byte* pBytes = &buffer[curIndex] ) {
                    Decode( pChars + startPos, pChars + startPos + len, pBytes, pBytes + ( endIndex - curIndex ), out charsDecoded, out bytesDecoded );
                }
            }
            curIndex += bytesDecoded;
            return charsDecoded;
        }