Add CFX_ByteStringC::CharAt() to avoid c_str() and casts

xfa/fxbarcode/datamatrix/BC_DataMatrixDecodedBitStreamParser.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 // Original code is licensed as follows:
 /*
  * Copyright 2008 ZXing authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ skipping 18 matching lines @@
     'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
     'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};
 const FX_CHAR CBC_DataMatrixDecodedBitStreamParser::C40_SHIFT2_SET_CHARS[] = {
     '!', '"', '#', '$', '%', '&', '\'', '(', ')', '*',  '+', ',', '-', '.',
     '/', ':', ';', '<', '=', '>', '?',  '@', '[', '\\', ']', '^', '_'};
 const FX_CHAR CBC_DataMatrixDecodedBitStreamParser::TEXT_BASIC_SET_CHARS[] = {
     '*', '*', '*', ' ', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
     'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
     'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
 const FX_CHAR CBC_DataMatrixDecodedBitStreamParser::TEXT_SHIFT3_SET_CHARS[] = {
-    '\'', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I',         'J',
-    'K',  'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',         'U',
-    'V',  'W', 'X', 'Y', 'Z', '{', '|', '}', '~', (FX_CHAR)127};
+    '\'', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
+    'K',  'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U',
+    'V',  'W', 'X', 'Y', 'Z', '{', '|', '}', '~', 127};
 const int32_t CBC_DataMatrixDecodedBitStreamParser::PAD_ENCODE = 0;
 const int32_t CBC_DataMatrixDecodedBitStreamParser::ASCII_ENCODE = 1;
 const int32_t CBC_DataMatrixDecodedBitStreamParser::C40_ENCODE = 2;
 const int32_t CBC_DataMatrixDecodedBitStreamParser::TEXT_ENCODE = 3;
 const int32_t CBC_DataMatrixDecodedBitStreamParser::ANSIX12_ENCODE = 4;
 const int32_t CBC_DataMatrixDecodedBitStreamParser::EDIFACT_ENCODE = 5;
 const int32_t CBC_DataMatrixDecodedBitStreamParser::BASE256_ENCODE = 6;
 CBC_DataMatrixDecodedBitStreamParser::CBC_DataMatrixDecodedBitStreamParser() {}
 CBC_DataMatrixDecodedBitStreamParser::~CBC_DataMatrixDecodedBitStreamParser() {}
 
@@ skipping 412 matching lines @@
   BC_FX_ByteString_Append(result, *bytes);
   delete bytes;
 }
 uint8_t CBC_DataMatrixDecodedBitStreamParser::Unrandomize255State(
     int32_t randomizedBase256Codeword,
     int32_t base256CodewordPosition) {
   int32_t pseudoRandomNumber = ((149 * base256CodewordPosition) % 255) + 1;
   int32_t tempVariable = randomizedBase256Codeword - pseudoRandomNumber;
   return (uint8_t)(tempVariable >= 0 ? tempVariable : tempVariable + 256);
 }