C ++ primer Reading Notes (12)

Standard exception classes in C ++

Namespace std

{

// Exception Derivation

Class logic_error; // logical error, which can be detected before running the program.

// Logic_error is derived.

Class domain_error; // The precondition is violated.

Class invalid_argument; // specifies an invalid parameter of the function.

Class length_error; // an attempt to point out an object that exceeds the maximum value of the present value of the size_t type

Class out_of_range; // parameter out of bounds

Class bad_cast; // an invalid dynamic_cast expression exists in the runtime type recognition.

Class bad_typeid; // report has a null pointer P in expression test typeid (* P)

// Exception Derivation

Class runtime_error; // runtime error, detected only during program running

// Runtime_error Derivation

Class range_error; // violates the post Condition

Class overflow_error; // report an arithmetic Overflow

Class bad_alloc; // Storage Allocation Error

}

 

Observe the hierarchy of the above classes. We can see that all standard exceptions are derived from a common base class exception. The base class contains necessary polymorphism functions that provide exception descriptions and can be overloaded. The following is the prototype of the exception class:

Class exception

{

Public:

Exception () Throw ();

Exception (const exception & RHs) Throw ();

Exception & operator = (const exception & RHs) Throw ();

Virtual ~ Exception () Throw ();

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

};

One of the important functions is what (), which returns a string pointer indicating an exception.