qDebug() << "Date:" << QDate::currentDate();
    qDebug() << "Types:" << QString("String") << QChar('x') << QRect(0, 10, 50, 40);
    qDebug() << "Custom coordinate type:" << coordinate;

QDebug operator<<(QDebug debug, const Coordinate &c)
{
    QDebugStateSaver saver(debug);
    debug.nospace() << '(' << c.x() << ", " << c.y() << ')';

    return debug;
}

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.

bool QDebug::autoInsertSpaces() const

Returns true if this QDebug instance will automatically insert spaces between writes.

This function was introduced in Qt 5.0.

See also setAutoInsertSpaces() and QDebugStateSaver.

QDebug & QDebug::maybeQuote(char c = '"')

Writes a character c to the debug stream, depending on the current setting for automatic insertion of quotes, and returns a reference to the stream.

The default character is a double quote ".

This function was introduced in Qt 5.4.

See also quote() and noquote().

QDebug & QDebug::maybeSpace()

Writes a space character to the debug stream, depending on the current setting for automatic insertion of spaces, and returns a reference to the stream.

See also space() and nospace().

QDebug & QDebug::noquote()

Disables automatic insertion of quotation characters around QChar, QString and QByteArray contents and returns a reference to the stream.

When quoting is disabled, these types are printed without quotation characters and without escaping of non-printable characters.

This function was introduced in Qt 5.4.

See also quote() and maybeQuote().

QDebug & QDebug::nospace()

Disables automatic insertion of spaces and returns a reference to the stream.

See also space() and maybeSpace().

QDebug & QDebug::quote()

Enables automatic insertion of quotation characters around QChar, QString and QByteArray contents and returns a reference to the stream.

Quoting is enabled by default.

This function was introduced in Qt 5.4.

See also noquote() and maybeQuote().

QDebug & QDebug::resetFormat()

Resets the stream formatting options, bringing it back to its original constructed state.

This function was introduced in Qt 5.4.

See also space() and quote().

void QDebug::setAutoInsertSpaces(bool b)

Enables automatic insertion of spaces between writes if b is true; otherwise automatic insertion of spaces is disabled.

This function was introduced in Qt 5.0.

See also autoInsertSpaces() and QDebugStateSaver.

QDebug & QDebug::space()

Writes a space character to the debug stream and returns a reference to the stream.

The stream remembers that automatic insertion of spaces is enabled for future writes.

See also nospace() and maybeSpace().

void QDebug::swap(QDebug & other)

Swaps this debug stream instance with other. This function is very fast and never fails.

This function was introduced in Qt 5.0.

QDebug & QDebug::operator<<(QChar t)

Writes the character, t, to the stream and returns a reference to the stream. Normally, QDebug prints control characters and non-US-ASCII characters as their C escape sequences or their Unicode value (\u1234). To print non-printable characters without transformation, enable the noquote() functionality, but note that some QDebug backends may not be 8-bit clean and may not be able to represent t.

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. The string is never quoted nor transformed to the output, but note that some QDebug backends might not be 8-bit clean.

QDebug & QDebug::operator<<(const QString & s)

Writes the string, s, to the stream and returns a reference to the stream. Normally, QDebug prints the string inside quotes and transforms non-printable characters to their Unicode values (\u1234).

To print non-printable characters without transformation, enable the noquote() functionality. Note that some QDebug backends might not be 8-bit clean.

Output examples:

QString s;

s = "a";
qDebug().noquote() << s;    // prints: a
qDebug() << s;              // prints: "a"

s = "\"a\r\n\"";
qDebug() << s;              // prints: "\"a\r\n\""

s = "\033";                 // escape character
qDebug() << s;              // prints: "\u001B"

s = "\u00AD";               // SOFT HYPHEN
qDebug() << s;              // prints: "\u00AD"

s = "\u00E1";               // LATIN SMALL LETTER A WITH ACUTE
qDebug() << s;              // prints: "á"

s = "a\u0301";              // "a" followed by COMBINING ACUTE ACCENT
qDebug() << s;              // prints: "á";

s = "\u0430\u0301";         // CYRILLIC SMALL LETTER A followed by COMBINING ACUTE ACCENT
qDebug() << s;              // prints: "а́"

QDebug & QDebug::operator<<(const QStringRef & s)

Writes the string, s, to the stream and returns a reference to the stream. Normally, QDebug prints the string inside quotes and transforms non-printable characters to their Unicode values (\u1234).

To print non-printable characters without transformation, enable the noquote() functionality. Note that some QDebug backends might not be 8-bit clean.

See the QString overload for examples.

QDebug & QDebug::operator<<(QLatin1String s)

Writes the string, s, to the stream and returns a reference to the stream. Normally, QDebug prints the string inside quotes and transforms non-printable characters to their Unicode values (\u1234).

To print non-printable characters without transformation, enable the noquote() functionality. Note that some QDebug backends might not be 8-bit clean.

See the QString overload for examples.

QDebug & QDebug::operator<<(const QByteArray & b)

Writes the byte array, b, to the stream and returns a reference to the stream. Normally, QDebug prints the array inside quotes and transforms control or non-US-ASCII characters to their C escape sequences (\xAB). This way, the output is always 7-bit clean and the string can be copied from the output and pasted back into C++ sources, if necessary.

To print non-printable characters without transformation, enable the noquote() functionality. Note that some QDebug backends might not be 8-bit clean.

Output examples:

QByteArray ba;

ba = "a";
qDebug().noquote() << ba;    // prints: a
qDebug() << ba;              // prints: "a"

ba = "\"a\r\n\"";
qDebug() << ba;              // prints: "\"a\r\n\""

ba = "\033";                 // escape character
qDebug() << ba;              // prints: "\x1B"

ba = "\xC3\xA1";
qDebug() << ba;              // prints: "\xC3\xA1"

ba = QByteArray("a\0b", 3);
qDebug() << ba               // prints: "\a\x00""b"

Note how QDebug needed to close and reopen the string in the way C and C++ languages concatenate string literals so that the letter 'b' is not interpreted as part of the previous hexadecimal escape sequence.

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.