[C++] Trim strings for fixed length arrays.

Author: mjpt777

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

@@ -1361,7 +1361,10 @@ private CharSequence generateArrayProperty(
  sb.append(String.format("\n" +
  indent + " std::string get%1$sAsString() const\n" +
  indent + " {\n" +
- indent + " std::string result(m_buffer + m_offset + %2$d, %3$d);\n" +
+ indent + " const char *buffer = m_buffer + m_offset + %2$d;\n" +
+ indent + " size_t length = 0;\n\n" +
+ indent + " for (; length < %3$d && *(buffer + length) != '\\0'; ++length);\n" +
+ indent + " std::string result(buffer, length);\n\n" +
  indent + " return result;\n" +
  indent + " }\n",
  toUpperFirstChar(propertyName),
@@ -1372,7 +1375,10 @@ private CharSequence generateArrayProperty(
  indent + " #if __cplusplus >= 201703L\n" +
  indent + " std::string_view get%1$sAsStringView() const SBE_NOEXCEPT\n" +
  indent + " {\n" +
- indent + " std::string_view result(m_buffer + m_offset + %2$d, %3$d);\n" +
+ indent + " const char *buffer = m_buffer + m_offset + %2$d;\n" +
+ indent + " size_t length = 0;\n\n" +
+ indent + " for (; length < %3$d && *(buffer + length) != '\\0'; ++length);\n" +
+ indent + " std::string_view result(buffer, length);\n\n" +
  indent + " return result;\n" +
  indent + " }\n" +
  indent + " #endif\n",