C + + exception handling

C + + exception handling

Translated from C + + complete refrence 3rd Chapter

The standard C + + library defines two exceptions-related libraries,<exception> and <stdexcept>. Exceptions are commonly used to report errors.

<exception>

<exception> defines classes, declarations, and functions that are related to exception handling.

Class Exception {

Public

Exception () throw ();

Exception (const char *const&);

Exception (const char *const&, int);

Exception (const bad_exception &OB) throw ();

Virtual ~exception () throw ();

Exception &operator= (const exception &ob) throw ();

Virtual const char *what (() const throw ();

};

Class Bad_exception:public Exception {

Public

Bad_exception () throw ();

Bad_exception (const bad_exception &ob) throw ();

Virtual ~bad_exception () throw ();

Bad_exception &operator= (const bad_exception &ob) throw ();

Virtual const char *what (() const throw ();

};

The exception class is the parent class for all exceptions in the C + + library. the Unexpected () function throws the bad_exception type. Each exception class overrides what () to return a string that describes the exception.

Some of the important classes are inherited from the exception class. The first one is Bad_alloc, which is thrown when the new operation fails. The other is Bad_typeid, which is thrown when the typeid operation is used incorrectly .

<exception> define the following declaration

Type	Defined
Terminate_handler	typedef void (*terminate_handler) ();
Unexpected_handler	typedef void (*unexpected_handler) ();

<exception> define the following function

Function	Describe
Terminater_handler set_terminate (terminate_handler fn) throw ();	Specifies the function that is called at the end of the program, and returns an old function pointer.
Unexpected_handler set_unexpected (unexpected_handler fn) throw ();	Ditto.
void terminate ();	This function is called by default abort () when there is an exception at the end of processing.
void Unexpected ();	Ditto

<stdexcept>

<stdexcept> defines a number of standard exception classes. There are two main categories: logic errors and run-time errors. Where run-time errors are not controlled by the programmer.

Logical errors are inherited from logic_error

exception	description
	domain error
invalid_argument	illegal parameters
length_error	Usually the object being created is too large for the given size
out_of_range< /span>	access hyper-bounds

Run-time errors are inherited from runtime_error

Abnormal	Describe
Overflow_error	Overflow
Range_error	Beyond the Presentation range
Underflow_error	Underflow

C + + exception handling