c++ - How can I delete a QSharedPointer -

i have written wrapper around qtextedit use qiodevice. want able use multiple wrapper same qtextedit, may use different text color each wrapper.

to make wrapper thread-safe added qmutex protect usage of qtextedit. thinking must use 1 mutex protect 1 qtextedit.

i end following implementation, using qsharedpointer protect qtextedit.

texteditiodevice.h

class texteditiodevice : public qiodevice {     q_object  public:     texteditiodevice(qtextedit * qtextedit, qcolor color, qobject * parent);      virtual ~texteditiodevice();  protected:     qint64 readdata(char *data, qint64 maxlen);      qint64 writedata(const char *data, qint64 len);  private:     /**      * @brief pointer qtextedit      */     qpointer<qtextedit> textedit;      /**      * @brief text color      */     qcolor color;      /**      * @brief shared pointer qtextedit associated mutex      */     qsharedpointer<qmutex> mutex;      /**      * @brief storage qtextedit associated mutexes      */     static qmap<qpointer<qtextedit>, qsharedpointer<qmutex>> mutexes; }; 

texteditiodevice.cpp

qmap<qpointer<qtextedit>, qsharedpointer<qmutex>> texteditiodevice::mutexes;  texteditiodevice::texteditiodevice(qtextedit * qtextedit, qcolor color, qobject * parent) :     qiodevice(parent),     textedit(qtextedit),     color(color) {     open(qiodevice::writeonly | qiodevice::text);      qregistermetatype<qtextcharformat>("qtextcharformat");     qregistermetatype<qtextblock>("qtextblock");     qregistermetatype<qtextcursor>("qtextcursor");      if(mutexes.contains(textedit))         mutex = mutexes[textedit];     else     {         mutex = qsharedpointer<qmutex>(new qmutex());         mutexes.insert(textedit, mutex);     } }  texteditiodevice::~texteditiodevice() { }  qint64 texteditiodevice::readdata(char *data, qint64 maxlen) {     q_unused(data);     q_unused(maxlen);     return 0; }    qint64 texteditiodevice::writedata(const char *data, qint64 len) {     if(textedit)     {         mutex->lock();         const qcolor lastcolor = textedit->textcolor();         textedit->settextcolor(color);         textedit->append(qstring(data));         textedit->settextcolor(lastcolor);         mutex->unlock();     }      return len; } 

i want know can remove qsharedpointer instance mutexes mapping qmutex deleted.

thanks help

as long shared pointer in static mutexes map, never deallocated, , lifetime of mutexes lifetime of program.

if want delete mutex, have remove mutexes mapping.