mlib::erc Class Reference

objects returned as a function result or thrown directly. More...

#include <errorcode.h>

Public Types
enum	level {   none = 0 , info , notice , warning ,   error , critical , alert , emerg }
	Error levels (borrowed from BSD Unix) More...

Public Member Functions
	erc ()
	Default ctor for erc objects creates an inactive error.
	erc (int value, level priority=level::error)
	Ctor for a real erc using default error facility.
	erc (int value, const mlib::errfac &facility, level priority=level::error)
	Ctor for a real erc.
	erc (const erc &other)
	Copy constructor removes the activity flag of the original object.
	erc (erc &&other)
	Move constructor removes the activity flag of the original object.
	~erc () noexcept(false)
	Destructor. Call raise() function to see if the error should get logged or thrown.
erc &	operator= (const erc &rhs)
	Principal assignment operator.
erc &	operator= (erc &&rhs)
	Move assignment operator.
	operator int () const
	Integer conversion operator.
level	priority () const
	Return priority value.
bool	is_active () const
	Return activity flag.
const errfac &	facility () const
	Return reference to facility.
bool	operator== (const erc &other) const
	Equality comparison operator.
bool	operator!= (const erc &other) const
	Inequality comparison operator.
void	raise () const
void	reactivate () const
	Similar to re-throwing an exception.
void	deactivate () const
	Marks error code as inactive.
int	code () const
	Return numerical value.
std::string	message () const
	Get logging message.
void	message (const std::string &m)
	Set the message for this error.

Static Public Attributes
static erc	success {0, erc::none}
	The SUCCESS indicator.

Friends
class	errfac

Detailed Description

objects returned as a function result or thrown directly.

If not tested and their level is above facility's logging level they will be logged (by calling errfac::log() ). If the level is above facility's throwing level they will be thrown as exceptions.

Member Enumeration Documentation

level

enum mlib::erc::level

Error levels (borrowed from BSD Unix)

Enumerator
none	always not logged, not thrown
info	default not logged, not thrown
notice	default not logged, not thrown
warning	default logged, not thrown
error	default logged, thrown
critical	default logged, thrown
alert	default logged, thrown
emerg	always logged, thrown

Constructor & Destructor Documentation

erc()

mlib::erc::erc ( const erc &  other )

inline

Copy constructor removes the activity flag of the original object.

Having two erc's active at the same time is a big no-no: when one of them is thrown, the stack unwinding process invokes the destructor of the other one, which in turn might throw again. Throwing an exception during stack unwinding will terminate your application. For more details see: https://isocpp.org/wiki/faq/exceptions#dtors-shouldnt-throw

However, the whole concept of erc's is based upon destructors throwing exceptions. Here we carefully navigate between a rock and a hard place.

Member Function Documentation

code()

int mlib::erc::code ( ) const

inline

Return numerical value.

As opposed to the integer conversion operator, this function doesn't change the activity flag.

deactivate()

void mlib::erc::deactivate ( ) const

inline

Marks error code as inactive.

Useful in catch clauses when we don't really care what the code value is.

message()

std::string mlib::erc::message ( ) const

inline

Get logging message.

Return message string associated this error.

If no message string has been attached to this object, it calls errfac::message() function to generate the message string.

operator int()

mlib::erc::operator int ( ) const

inline

Integer conversion operator.

Assume the error has been dealt with and reset the active flag.

operator!=()

bool mlib::erc::operator!= ( const erc &  other ) const

inline

Inequality comparison operator.

All success codes are equal. Other codes are equal only if their value, level and facility are equal.

Resets the activity flag.

operator=() [1/2]

erc & mlib::erc::operator= ( const erc &  rhs )

inline

Principal assignment operator.

If we were active before, call the facility to log or throw. Anyhow copy new values from the assigned object and take away it's active flag.

Note

It is rather bad practice to assign to an active erc object. Here we take the view that, since the left side object was already active, we have to deal with it first.

operator=() [2/2]

erc & mlib::erc::operator= ( erc &&  rhs )

inline

Move assignment operator.

If we were active before, call the facility to log or throw. Anyhow copy new values from the assigned object and take away it's active flag.

operator==()

bool mlib::erc::operator== ( const erc &  other ) const

inline

Equality comparison operator.

All success codes are equal. Other codes are equal only if their value, level and facility are equal.

Resets the activity flag.

raise()

void mlib::erc::raise ( ) const

inline

Invoke facility's raise function (errfac::raise) to determine if error code should be logged or thrown

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The documentation for this class was generated from the following file:

• include/mlib/errorcode.h