enum ExceptionType : ubyte {

  NOT_ZERO_ROWS, ///

  STRICTLY_ONE_ROW, ///

  NOT_MORE_THAN_ONE_ROW, ///

}

​

import std.exception;

import std.conv: to;

​

pure @safe string generateBaseMessage(ExceptionType type)

{

    final switch(type) {

      case ExceptionType.NOT_ZERO_ROWS:

        return `Zero rows affected`;

​

      case ExceptionType.STRICTLY_ONE_ROW:

        return `Strictly one row should be affected`;

​

      case ExceptionType.NOT_MORE_THAN_ONE_ROW:

        return `Not more than one row should be affected`;

    }

}

class SearchException : Exception {

  const ExceptionType type;

​

  this(ExceptionType t, long rowsNum, string file = __FILE__, size_t line = __LINE__) pure @safe {

    type = t;

​

    string msg = generateBaseMessage(type);

​

    /*final switch(type) {

      case ExceptionType.NOT_ZERO_ROWS:

        msg = `Zero rows affected`;

        break;

​

      case ExceptionType.STRICTLY_ONE_ROW:

        msg = `Strictly one row should be affected`;

        break;

​

      case ExceptionType.NOT_MORE_THAN_ONE_ROW:

        msg = `Not more than one row should be affected`;

        break;

    }*/

    msg ~=`, not ` ~ rowsNum.to!string;

​

    super(msg, file, line); ///WTF? Error: constructor calls not allowed in loops or after labels

  }

}

​