[C++] Non-printable CHAR printed as int

Author: trozen

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/cpp/CppGenerator.java

@@ -2532,7 +2532,12 @@ private CharSequence writeTokenDisplay(
  // have to duplicate because of checkstyle :/
  if (typeToken.encoding().primitiveType() == PrimitiveType.CHAR)
  {
- sb.append(indent + "builder << '\"' << (char)" + fieldName + "() << '\"';\n");
+ sb.append(
+ indent + "if (std::isprint(" + fieldName + "())) {\n" +
+ indent + " builder << '\"' << (char)" + fieldName + "() << '\"';\n" +
+ indent + "} else {\n" +
+ indent + " builder << (int)" + fieldName + "();\n" +
+ indent + "}\n");
  }
  else
  {