message: tostring: use switch/case instead of map for enum -> string
diff: namespace adios2
  {
  -namespace
  +std::string ToString(ShapeID value)
  {
  + switch (value)
  + {
  + case ShapeID::Unknown:
  + return "ShapeID::Unknown";
  + case ShapeID::GlobalValue:
  + return "ShapeID::GlobalValue";
  + case ShapeID::GlobalArray:
  + return "ShapeID::GlobalArray";
  + case ShapeID::JoinedArray:
  + return "ShapeID::JoinedArray";
  + case ShapeID::LocalValue:
  + return "ShapeID::LocalValue";
  + case ShapeID::LocalArray:
  + return "ShapeID::LocalArray";
  + default:
  + return "ToString: Unknown ShapeID";
  + }
  +}
  -std::map<ShapeID, std::string> MapShapeID2String = {
  - {ShapeID::Unknown, "ShapeID::Unknown"},
  - {ShapeID::GlobalValue, "ShapeID::GlobalValue"},
  - {ShapeID::GlobalArray, "ShapeID::GlobalArray"},
  - {ShapeID::JoinedArray, "ShapeID::JoinedArray"},
  - {ShapeID::LocalValue, "ShapeID::LocalValue"},
  - {ShapeID::LocalArray, "ShapeID::LocalArray"},
  -};
  -
  -std::map<IOMode, std::string> MapIOMode2String = {
  - {IOMode::Independent, "IOMode::Independent"},
  - {IOMode::Collective, "IOMode::Collective"},
  -};
  -
  -std::map<Mode, std::string> MapMode2String = {
  - {Mode::Undefined, "Mode::Undefined"}, {Mode::Write, "Mode::Write"},
  - {Mode::Read, "Mode::Read"}, {Mode::Append, "Mode::Append"},
  - {Mode::Sync, "Mode::Sync"}, {Mode::Deferred, "Mode::Deferred"},
  -};
  -
  -} // end anonymous namespace
  -
  -std::string ToString(ShapeID value) { return MapShapeID2String.at(value); }
  -
  -std::string ToString(IOMode value) { return MapIOMode2String.at(value); }
  +std::string ToString(IOMode value)
  +{
  + switch (value)
  + {
  + case IOMode::Independent:
  + return "IOMode::Independent";
  + case IOMode::Collective:
  + return "IOMode::Collective";
  + default:
  + return "ToString: Unknown IOMode";
  + }
  +}
  -std::string ToString(Mode value) { return MapMode2String.at(value); }
  +std::string ToString(Mode value)
  +{
  + switch (value)
  + {
  + case Mode::Undefined:
  + return "Mode::Undefined";
  + case Mode::Write:
  + return "Mode::Write";
  + case Mode::Read:
  + return "Mode::Read";
  + case Mode::Append:
  + return "Mode::Append";
  + case Mode::Sync:
  + return "Mode::Sync";
  + case Mode::Deferred:
  + return "Mode::Deferred";
  + default:
  + return "ToString: Unknown Mode";
  + }
  +}
  } // end namespace adios2
  