QDeadlineTimer: inline the isForever function

The constructor that sets it is inline already, so there's no point in
hiding this.

Change-Id: I66707fdfe8eb460a9c72fffd146d8dbc35b13056
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

src/corelib/kernel/qdeadlinetimer.cpp

@@ -408,16 +408,14 @@ void QDeadlineTimer::setPreciseRemainingTime(qint64 secs, qint64 nsecs, Qt::Time
 */
 
 /*!
+    \fn bool QDeadlineTimer::isForever() const
+
     Returns true if this QDeadlineTimer object never expires, false otherwise.
     For timers that never expire, remainingTime() always returns -1 and
     deadline() returns the maximum value.
 
     \sa ForeverConstant, hasExpired(), remainingTime()
 */
-bool QDeadlineTimer::isForever() const Q_DECL_NOTHROW
-{
-    return t1 == (std::numeric_limits<qint64>::max)();
-}
 
 /*!
     Returns true if this QDeadlineTimer object has expired, false if there

src/corelib/kernel/qdeadlinetimer.h

@@ -65,7 +65,8 @@ public:
     void swap(QDeadlineTimer &other)
     { qSwap(t1, other.t1); qSwap(t2, other.t2); qSwap(type, other.type); }
 
-    bool isForever() const Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR bool isForever() const Q_DECL_NOTHROW
+    { return t1 == (std::numeric_limits<qint64>::max)(); }
     bool hasExpired() const Q_DECL_NOTHROW;
 
     Qt::TimerType timerType() const Q_DECL_NOTHROW