The class also provides several constructors for other situations, including a constructor that accepts a QFile or any other QIODevice subclass that is used to write debugging information to files and other devices. The constructor that accepts a QString is used to write to a string for display or serialization.
Writing Custom Types to a Stream
Many standard types can be written to QDebug objects, and Qt provides support for most Qt value types. To add support for custom types, you need to implement a streaming operator, as in the following example:
QDebug operator<<(QDebug dbg, const Coordinate &c)
{
dbg.nospace() << "(" << c.x() << ", " << c.y() << ")";
return dbg.space();
}
This is described in the Debugging Techniques and Creating Custom Qt Types documents.
Member Function Documentation
QDebug::QDebug ( QIODevice * device )
Constructs a debug stream that writes to the given device.
QDebug::QDebug ( QString * string )
Constructs a debug stream that writes to the given string.
QDebug::QDebug ( QtMsgType type )
Constructs a debug stream that writes to the handler for the message type specified by type.
QDebug::QDebug ( const QDebug & other )
Constructs a copy of the other debug stream.
QDebug::~QDebug ()
Flushes any pending data to be written and destroys the debug stream.
QDebug & QDebug::maybeSpace ()
Writes a space character to the debug stream, depending on the last character sent to the stream, and returns a reference to the stream.
If the last character was a space character, this function writes a space character to the stream; otherwise, no characters are written to the stream.
See also space() and nospace().
QDebug & QDebug::nospace ()
Clears the stream's internal flag that records whether the last character was a space and returns a reference to the stream.
See also space() and maybeSpace().
QDebug & QDebug::space ()
Writes a space character to the debug stream and returns a reference to the stream.
The stream will record that the last character sent to the stream was a space.
See also nospace() and maybeSpace().
QDebug & QDebug::operator<< ( QChar t )
Writes the character, t, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( bool t )
Writes the boolean value, t, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( char t )
Writes the character, t, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( signed short i )
Writes the signed short integer, i, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( unsigned short i )
Writes then unsigned short integer, i, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( signed int i )
Writes the signed integer, i, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( unsigned int i )
Writes then unsigned integer, i, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( signed long l )
Writes the signed long integer, l, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( unsigned long l )
Writes then unsigned long integer, l, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( qint64 i )
Writes the signed 64-bit integer, i, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( quint64 i )
Writes then unsigned 64-bit integer, i, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( float f )
Writes the 32-bit floating point number, f, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( double f )
Writes the 64-bit floating point number, f, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( const char * s )
Writes the '\0'-terminated string, s, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( const QString & s )
Writes the string, s, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( const QStringRef & s )
Writes the string reference, s, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( const QLatin1String & s )
Writes the Latin1-encoded string, s, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( const QByteArray & b )
Writes the byte array, b, to the stream and returns a reference to the stream.
QDebug & QDebug::operator<< ( const void * p )
Writes a pointer, p, to the stream and returns a reference to the stream.
QDebug & QDebug::operator= ( const QDebug & other )
Assigns the other debug stream to this stream and returns a reference to this stream.
