C + + Exception Second---C + + standard Library Exception class exception use __c++

1 Inheritance Diagram

2 Specific explanations

C + + Standard library Exception class inheritance hierarchy in the root class is exception, which is defined in the exception header file, it is the C + + standard library all functions throw exception of the base class, exception interface definition is as follows:

Namespace Std {

Class Exception {

Public

Exception () throw (); Do not throw any exceptions

Exception (const exception& e) throw ();

exception& operator= (const exception& e) throw ();

Virtual ~exception () throw) ();

Virtual Const char* What () const throw (); Returns a description of the exception

};

}

In addition to the exception class, C + + provides classes for reporting abnormal programs, and in the error models reflected in these predefined classes, there are two broad categories of logic errors and run-time errors.

Logic errors mainly include Invalid_argument, Out_of_range, Length_error, Domain_error. When a function receives an invalid argument, it throws a Invaild_argument exception, and if the function receives an argument that is outside the expected range, it throws a Out_of_range exception, and so on.

Namespace Std {

Class Logic_error:public Exception {

Public

Explicit Logic_error (const string &what_arg);

};

Class Invalid_argument:public Logic_error {

Public

Explicit invalid_argument (const string &what_arg);

};

Class Out_of_range:public Logic_error {

Public

Explicit Out_of_range (const string &what_arg);

};

Class Length_error:public Logic_error {

Public

Explicit Length_error (const string &what_arg);

};

Class Domain_error:public Logic_error {

Public

Explicit Domain_error (const string &what_arg);

};

}

Run-time errors are raised by events outside the program domain and can only be detected at run time, mainly including Range_error, Overflow_error, Underflow_error. A function can report a range error in an arithmetic operation by throwing a range_eroor, and reporting an overflow error by throwing a overflow_error.

Namespace Std {

Class Runtime_error:public Exception {

Public

Explicit Runtime_error (const string &what_arg);

};

Class Range_error:public Runtime_error {

Public

Explicit Range_error (const string &what_arg);

};

Class Overflow_error:public Runtime_error {

Public

Explicit Overflow_error (const string &what_arg);

};

Class Underflow_error:public Runtime_error {

Public

Explicit Underflow_error (const string &what_arg);

};

}

In addition, the BAD_ALLOC exception is defined in the new header file, and exception is also a Bad_alloc base class for reporting cases where the new operator does not properly allocate memory. When dynamic_cast fails, the program throws the Bad_cast exception class, which also inherits from the exception class.

Reproduced from: http://blog.csdn.net/zhq651/article/details/8425579

3 Examples

#include <stdexcept>

Try
  {
  throw invalid_argument ("hah");
 //throw out_of_range ("We get the Outofrange err or ");
   }catch (invalid_argument& in)
  {
  cout<< "We catch Invalid_argument" <& Lt;in.what () <<endl;
 }catch (...)
  {
  cout<< "We catch unexpected Error,exit" <<ENDL;
  return 1;
 }