Dv::ostream_ptr Class Reference

The following functions support writing to a std::ostream* If the pointer is 0 (null), nothing is written. More...

#include <debug.h>

List of all members.

Public Member Functions
	ostream_ptr (std::ostream *ostrm=0)
	Constructor.
	~ostream_ptr ()
	Destructor.
bool	null () const
std::ostream *	set_os (std::ostream *ostrm)
	Update the underlying std::ostream pointer.
std::ostream *	ostrm () const
ostream_ptr &	operator= (std::ostream *ostrm)
	Update the underlying std::ostream pointer using assignment.
Private Attributes
std::ostream *	os
Friends
template<typename T >
ostream_ptr &	operator<< (ostream_ptr &osp, const T &t)
	Generic writing to an ostream_ptr.
template<typename T >
ostream_ptr &	operator<< (ostream_ptr &osp, const T *t)
	Specialization for writing a pointer to an ostream_ptr.
ostream_ptr &	operator<< (ostream_ptr &osp, std::ostream &(*pf)(std::ostream &))
	This function supports writing some io manipulators such as std::endl or std::setw to an ostream_ptr.

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Detailed Description

The following functions support writing to a std::ostream* If the pointer is 0 (null), nothing is written.

Otherwise, operator<< behaves as on std::ostream.

This is useful e.g. when one has a

 std::ostream* log;

variable which may be 0 (if logging is turned off). One may then write

 ostream_ptr(log) << "blabla" << std::endl;

instead of cluttering with

 if (log)
   *log << "blabla" << std::endl;

Note that in order to support

  operator<<(ostream_ptr& osp, const T& t) {

we need to package std::ostream* into its own class since overloaded operators need at least one user defined operand type.

See also:

Dv::Debugable

Dv::DebuSlave

Dv::Debug

Definition at line 41 of file debug.h.

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Constructor & Destructor Documentation

Dv::ostream_ptr::ostream_ptr

(

std::ostream *

ostrm = 0

)

[inline]

Constructor.

Parameters:

ostrm

underlying std::ostream pointer or 0

Definition at line 46 of file debug.h.

Dv::ostream_ptr::~ostream_ptr

(

)

[inline]

Destructor.

Definition at line 50 of file debug.h.

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Member Function Documentation

bool Dv::ostream_ptr::null

(

)

const [inline]

Returns:

true if this is a null Dv::ostream_ptr, i.e. the underlying std::ostream pointer is 0

Definition at line 56 of file debug.h.

References os.

std::ostream* Dv::ostream_ptr::set_os

(

std::ostream *

ostrm

)

[inline]

Update the underlying std::ostream pointer.

Parameters:

ostrm

new underlying std::ostream pointer or 0

Returns:

old underlying std::ostream pointer

Definition at line 63 of file debug.h.

References os.

Referenced by operator=(), and Dv::Debug::set_log().

std::ostream* Dv::ostream_ptr::ostrm

(

)

const [inline]

Definition at line 71 of file debug.h.

References os.

ostream_ptr& Dv::ostream_ptr::operator=

(

std::ostream *

ostrm

)

[inline]

Update the underlying std::ostream pointer using assignment.

Parameters:

ostrm

new underlying std::ostream pointer or 0

Returns:

*this

See also:

Dv::ostream_ptr::set_os

Definition at line 81 of file debug.h.

References set_os().

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Friends And Related Function Documentation

template<typename T >

ostream_ptr& operator<<	(	ostream_ptr &	osp,
		const T &	t
	)			[friend]

Generic writing to an ostream_ptr.

If the underlying stream is 0, nothing will be written, obviously.

Parameters:

	osp	ostream_ptr with underlying stream (or 0) to write to
	t	object to write

Returns:

osp, which may have been zeroed if the write operation failed

Definition at line 95 of file debug.h.

template<typename T >

ostream_ptr& operator<<	(	ostream_ptr &	osp,
		const T *	t
	)			[friend]

Specialization for writing a pointer to an ostream_ptr.

If the underlying stream is 0, nothing will be written, obviously.

Parameters:

	osp	ostream_ptr with underlying stream (or 0) to write to
	t	object to write

Returns:

osp, which may have been zeroed if the write operation failed

Definition at line 112 of file debug.h.

ostream_ptr& operator<<	(	ostream_ptr &	osp,
		std::ostream &(*)(std::ostream &)	pf
	)			[friend]

This function supports writing some io manipulators such as std::endl or std::setw to an ostream_ptr.

Parameters:

	osp	stream to write to
	pf	io manipulator to write

Returns:

osp, which may have been zeroed if the write operation failed

Definition at line 128 of file debug.h.

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Member Data Documentation

std::ostream* Dv::ostream_ptr::os [private]

Definition at line 137 of file debug.h.

Referenced by null(), ostrm(), and set_os().

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

• debug.h