Message Class Reference

Abstract class which defines the interface for all types of message. More...

#include <keyvalue/sys/message/Message.h>

Inheritance diagram for Message:

List of all members.

Public Member Functions
unsigned int	getLevel () const
	Gets Message's level.
string	getString () const
	Gets Message's text.
virtual const string &	getPrefix () const =0
	Gets Message's prefix.
virtual logger::Colour	getColour () const =0
	Gets Message's colour.
template<typename DataType >
Message &	operator& (const DataType &data)
	Appends data to the end of message.
Protected Member Functions
	Message (unsigned int level)
	Constructs a Message with a given level.
	Message (const Message &orig)
Static Protected Attributes
static const Traits_	traits_ []
Private Member Functions
Message &	operator= (const Message &orig)
Private Attributes
unsigned int	level_
mutable::std::ostringstream	buf_

---

Detailed Description

Abstract class which defines the interface for all types of message.

Each Message has a level that defines if it will be ignored or not by the Logger which receives it. (For more details, see Logger documentation).

---

Constructor & Destructor Documentation

Message

(

unsigned int

level

)

[explicit, protected]

Constructs a Message with a given level.

Parameters:

level

: Message's level.

---

Member Function Documentation

unsigned int getLevel

(

)

const

Gets Message's level.

Returns:

The level.

string getString

(

)

const

Gets Message's text.

Returns:

The text.

virtual const string& getPrefix

(

)

const [pure virtual]

Gets Message's prefix.

Returns:

The prefix.

Implemented in MessageImpl< id >.

virtual logger::Colour getColour

(

)

const [pure virtual]

Gets Message's colour.

Returns:

The colour.

Implemented in MessageImpl< id >.

Message & operator&

(

const DataType &

data

)

Appends data to the end of message.

This template method makes use of std::ostream::operator<<() to append data to this Message. Hence, the type of data DataType must be such that std::ostream::operator<<(ostream&, const DataType&) is well defined.

A typical use of this method is

 Info info(1);  // Info is derived from Message
 size_t i;
 vector<double> x;
 // ...
 info & "x[" & i & "] = " & x[i];

Warning: For some reason, one cannot append std::endl to Message, despite the fact that a standard ostream can accept it!

Remark: It would be more natural using operator<< rather than operator&. However, the main use of operator& is related to exceptions (see exception::ExceptionImpl documentation). Indeed, there exist ExceptionImpl::operator&() which just redirects its call to this operator& here. In the past, KeyValue exceptions were derived from boost::exception which defines operator<< for other purposes. Therefore, operator& was preferred rather than operator<< to avoid conflict with boost. Be aware that, in the near future, if it is proven convenient, one might change operator& to operator<< again.

Parameters:

	DataType	: (template parameter) Type of data;
	data	: the data to be appended.