[C++] Use brace-equal initializers for default constructors.

Author: denizevrenci

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

@@ -1374,9 +1374,9 @@ private CharSequence generateFixedFlyweightCode(final String className, final in
 
  return String.format(
  "private:\n" +
- " char *m_buffer;\n" +
+ " char *m_buffer = nullptr;\n" +
  " std::uint64_t m_bufferLength;\n" +
- " std::uint64_t m_offset;\n" +
+ " std::uint64_t m_offset = 0;\n" +
  " std::uint64_t m_actingVersion;\n\n" +
  " inline void reset(char *buffer, const std::uint64_t offset, const std::uint64_t bufferLength," +
  " const std::uint64_t actingVersion)\n" +
@@ -1391,7 +1391,7 @@ private CharSequence generateFixedFlyweightCode(final String className, final in
  " m_actingVersion = actingVersion;\n" +
  " }\n\n" +
  "public:\n" +
- " %1$s() : m_buffer(nullptr), m_offset(0) {}\n\n" +
+ " %1$s() = default;\n\n" +
  " %1$s(char *buffer, const std::uint64_t bufferLength, const std::uint64_t actingVersion)\n" +
  " {\n" +
  " reset(buffer, 0, bufferLength, actingVersion);\n" +
@@ -1441,7 +1441,7 @@ private CharSequence generateFixedFlyweightCode(final String className, final in
  private static CharSequence generateConstructorsAndOperators(final String className)
  {
  return String.format(
- " %1$s() : m_buffer(nullptr), m_bufferLength(0), m_offset(0) {}\n\n" +
+ " %1$s() = default;\n\n" +
  " %1$s(char *buffer, const std::uint64_t bufferLength)\n" +
  " {\n" +
  " reset(buffer, 0, bufferLength, sbeBlockLength(), sbeSchemaVersion());\n" +
@@ -1473,10 +1473,10 @@ private CharSequence generateMessageFlyweightCode(final String className, final
 
  return String.format(
  "private:\n" +
- " char *m_buffer;\n" +
- " std::uint64_t m_bufferLength;\n" +
+ " char *m_buffer = nullptr;\n" +
+ " std::uint64_t m_bufferLength = 0;\n" +
  " std::uint64_t *m_positionPtr;\n" +
- " std::uint64_t m_offset;\n" +
+ " std::uint64_t m_offset = 0;\n" +
  " std::uint64_t m_position;\n" +
  " std::uint64_t m_actingBlockLength;\n" +
  " std::uint64_t m_actingVersion;\n\n" +