Exceptions for Error Reporting

1. Debug mode: Exceptions thrown by the code (no by STL functions) must be inside a debug mode condition set in the ADIOS class constructor. Applications are encourages to turn these on when integrating with ADIOS2.

2. Throw C++ standard exceptions: do not throw integers. This is helpful as it allows handling of different exception types in different ways.

   • Don't

     throw 1;

   • Do

     throw std::invalid_argument ( "ERROR: variable + variableName + "was not   
                                    previously declared, in call to Write;" );

3. Document exceptions: All error exceptions must start with "ERROR: ". Use informative and precise messages to help the user identify and fix the issue.

   • Don't

     throw std::invalid_argument( "ERROR: invalid input for bzip2_blockSize100K" );

   • Do

     throw std::invalid_argument( "ERROR: bzip2_blockSize100K parameters 
                                   must be between 0 and 9,  
                                   in call to AddTransform"  );