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Deallocate memory to singleton class which access database ?

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  • Q Qt embedded developer

    @jsulm Okay thanks. but still i am getting below errors:

    "src\SqliteManagerBGSync.cpp", line 27: Error: #260-D: explicit type is missing ("int" assumed)
    for (const auto& kv : sqliteManagerMap) {
    ^
    "src\SqliteManagerBGSync.cpp", line 27: Error: #252: reference variable "kv" requires an initializer
    for (const auto& kv : sqliteManagerMap) {
    ^
    "src\SqliteManagerBGSync.cpp", line 27: Error: #65: expected a ";"
    for (const auto& kv : sqliteManagerMap) {
    ^
    "src\SqliteManagerBGSync.cpp", line 27: Error: #29: expected an expression
    for (const auto& kv : sqliteManagerMap) {
    ^
    "src\SqliteManagerBGSync.cpp", line 27: Error: #65: expected a ";"
    for (const auto& kv : sqliteManagerMap) {
    ^
    "src\SqliteManagerBGSync.cpp", line 28: Error: #153: expression must have class type
    delete kv.second;

    KroMignonK Offline
    KroMignonK Offline
    KroMignon
    wrote on last edited by KroMignon
    #13

    @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

    Okay thanks. but still i am getting below errors:

    Do your compiler support C++11 and did you enable C++11 support (eg. add CONFIG += c++11 in your PRO file)?

    It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

    Q 1 Reply Last reply
    2
    • KroMignonK KroMignon

      @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

      Okay thanks. but still i am getting below errors:

      Do your compiler support C++11 and did you enable C++11 support (eg. add CONFIG += c++11 in your PRO file)?

      Q Offline
      Q Offline
      Qt embedded developer
      wrote on last edited by Qt embedded developer
      #14

      @KroMignon Hi i am not using qt . and sorry i can not enable C++ 11 because my compiler not support it. i can access map like std::map .

      KroMignonK 1 Reply Last reply
      0
      • Q Qt embedded developer

        @jsulm Okay thanks. but still i am getting below errors:

        "src\SqliteManagerBGSync.cpp", line 27: Error: #260-D: explicit type is missing ("int" assumed)
        for (const auto& kv : sqliteManagerMap) {
        ^
        "src\SqliteManagerBGSync.cpp", line 27: Error: #252: reference variable "kv" requires an initializer
        for (const auto& kv : sqliteManagerMap) {
        ^
        "src\SqliteManagerBGSync.cpp", line 27: Error: #65: expected a ";"
        for (const auto& kv : sqliteManagerMap) {
        ^
        "src\SqliteManagerBGSync.cpp", line 27: Error: #29: expected an expression
        for (const auto& kv : sqliteManagerMap) {
        ^
        "src\SqliteManagerBGSync.cpp", line 27: Error: #65: expected a ";"
        for (const auto& kv : sqliteManagerMap) {
        ^
        "src\SqliteManagerBGSync.cpp", line 28: Error: #153: expression must have class type
        delete kv.second;

        J.HilkJ Offline
        J.HilkJ Offline
        J.Hilk
        Moderators
        wrote on last edited by
        #15

        @Qt-embedded-developer

        SqliteManagerBGSync();
        cleanup();
        

        both are missing the return type, and also make sure to fix them in the *.cpp file as well!


        Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


        Q: What's that?
        A: It's blue light.
        Q: What does it do?
        A: It turns blue.

        Q 1 Reply Last reply
        0
        • J.HilkJ J.Hilk

          @Qt-embedded-developer

          SqliteManagerBGSync();
          cleanup();
          

          both are missing the return type, and also make sure to fix them in the *.cpp file as well!

          Q Offline
          Q Offline
          Qt embedded developer
          wrote on last edited by
          #16

          @J-Hilk i have changed it . i have used void, But still i am getting as below mentioned error:

          "src\SqliteManagerBGSync.cpp", line 27: Error: #260-D: explicit type is missing ("int" assumed)
          for (const auto& kv : sqliteManagerMap) {
          ^
          "src\SqliteManagerBGSync.cpp", line 27: Error: #252: reference variable "kv" requires an initializer
          for (const auto& kv : sqliteManagerMap) {
          ^
          "src\SqliteManagerBGSync.cpp", line 27: Error: #65: expected a ";"
          for (const auto& kv : sqliteManagerMap) {
          ^
          "src\SqliteManagerBGSync.cpp", line 27: Error: #29: expected an expression
          for (const auto& kv : sqliteManagerMap) {
          ^
          "src\SqliteManagerBGSync.cpp", line 27: Error: #65: expected a ";"
          for (const auto& kv : sqliteManagerMap) {
          ^
          "src\SqliteManagerBGSync.cpp", line 28: Error: #153: expression must have class type
          delete kv.second;

          jsulmJ 1 Reply Last reply
          0
          • Q Qt embedded developer

            @J-Hilk i have changed it . i have used void, But still i am getting as below mentioned error:

            "src\SqliteManagerBGSync.cpp", line 27: Error: #260-D: explicit type is missing ("int" assumed)
            for (const auto& kv : sqliteManagerMap) {
            ^
            "src\SqliteManagerBGSync.cpp", line 27: Error: #252: reference variable "kv" requires an initializer
            for (const auto& kv : sqliteManagerMap) {
            ^
            "src\SqliteManagerBGSync.cpp", line 27: Error: #65: expected a ";"
            for (const auto& kv : sqliteManagerMap) {
            ^
            "src\SqliteManagerBGSync.cpp", line 27: Error: #29: expected an expression
            for (const auto& kv : sqliteManagerMap) {
            ^
            "src\SqliteManagerBGSync.cpp", line 27: Error: #65: expected a ";"
            for (const auto& kv : sqliteManagerMap) {
            ^
            "src\SqliteManagerBGSync.cpp", line 28: Error: #153: expression must have class type
            delete kv.second;

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #17

            @Qt-embedded-developer As @KroMignon already asked you: do you have a C++11 capable compiler? And is C++11 activated?

            https://forum.qt.io/topic/113070/qt-code-of-conduct

            Q 1 Reply Last reply
            1
            • jsulmJ jsulm

              @Qt-embedded-developer As @KroMignon already asked you: do you have a C++11 capable compiler? And is C++11 activated?

              Q Offline
              Q Offline
              Qt embedded developer
              wrote on last edited by Qt embedded developer
              #18

              @jsulm no i have not. So what i have to change in below function:

              SqliteManagerBGSync::cleanup()
              {
              for (const auto& kv : sqliteManagerMap) {
                  delete kv.second;
              }
              sqliteManagerMap.clear();
              
              }
              
              jsulmJ 1 Reply Last reply
              0
              • Q Qt embedded developer

                @KroMignon Hi i am not using qt . and sorry i can not enable C++ 11 because my compiler not support it. i can access map like std::map .

                KroMignonK Offline
                KroMignonK Offline
                KroMignon
                wrote on last edited by KroMignon
                #19

                @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

                Hi i am not using qt . and sorry i can not enable C++ 11. i can access map like std::map .

                The problem is not std::map<>() but the way you iterate through the map: for (const auto& kv : sqliteManagerMap) requires at least C++11 support enabled! (cf. https://en.cppreference.com/w/cpp/container/map)

                I don't know which kind of C++ compiler you are using, for GCC for example enabling C++11 is done with -std=c++11 or -std=gnu++11

                It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

                Q 1 Reply Last reply
                3
                • Q Qt embedded developer

                  @jsulm no i have not. So what i have to change in below function:

                  SqliteManagerBGSync::cleanup()
                  {
                  for (const auto& kv : sqliteManagerMap) {
                      delete kv.second;
                  }
                  sqliteManagerMap.clear();
                  
                  }
                  
                  jsulmJ Offline
                  jsulmJ Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on last edited by
                  #20

                  @Qt-embedded-developer Then you can't use auto, write the type instead of auto

                  https://forum.qt.io/topic/113070/qt-code-of-conduct

                  1 Reply Last reply
                  1
                  • KroMignonK KroMignon

                    @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

                    Hi i am not using qt . and sorry i can not enable C++ 11. i can access map like std::map .

                    The problem is not std::map<>() but the way you iterate through the map: for (const auto& kv : sqliteManagerMap) requires at least C++11 support enabled! (cf. https://en.cppreference.com/w/cpp/container/map)

                    I don't know which kind of C++ compiler you are using, for GCC for example enabling C++11 is done with -std=c++11 or -std=gnu++11

                    Q Offline
                    Q Offline
                    Qt embedded developer
                    wrote on last edited by
                    #21

                    @KroMignon i can not enable it like that because any change like that not allowed in my device.

                    J.HilkJ KroMignonK 2 Replies Last reply
                    0
                    • Q Qt embedded developer

                      @KroMignon i can not enable it like that because any change like that not allowed in my device.

                      J.HilkJ Offline
                      J.HilkJ Offline
                      J.Hilk
                      Moderators
                      wrote on last edited by
                      #22

                      @Qt-embedded-developer than do a normal for(x; x<y; ++x) loop


                      Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                      Q: What's that?
                      A: It's blue light.
                      Q: What does it do?
                      A: It turns blue.

                      Q 1 Reply Last reply
                      1
                      • J.HilkJ J.Hilk

                        @Qt-embedded-developer than do a normal for(x; x<y; ++x) loop

                        Q Offline
                        Q Offline
                        Qt embedded developer
                        wrote on last edited by
                        #23

                        @J-Hilk ,@jsulm ,@jsulm ,@KroMignon Thanks for enormous support.

                        i have written like it below and now its not show any error:

                        void SqliteManagerBGSync::cleanup()
                        {
                        for (short int i =0 ; i<sizeof(sqliteManagerMap);i++)
                        {
                            delete sqliteManagerMap[i];
                        }
                        sqliteManagerMap.clear();
                        
                        }
                        
                        J.HilkJ 1 Reply Last reply
                        0
                        • Q Qt embedded developer

                          @J-Hilk ,@jsulm ,@jsulm ,@KroMignon Thanks for enormous support.

                          i have written like it below and now its not show any error:

                          void SqliteManagerBGSync::cleanup()
                          {
                          for (short int i =0 ; i<sizeof(sqliteManagerMap);i++)
                          {
                              delete sqliteManagerMap[i];
                          }
                          sqliteManagerMap.clear();
                          
                          }
                          
                          J.HilkJ Offline
                          J.HilkJ Offline
                          J.Hilk
                          Moderators
                          wrote on last edited by
                          #24

                          @Qt-embedded-developer
                          using sizeof is almost certainly wrong here.

                          std::map has a size() function, please use that.
                          https://en.cppreference.com/w/cpp/container/map/size


                          Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                          Q: What's that?
                          A: It's blue light.
                          Q: What does it do?
                          A: It turns blue.

                          1 Reply Last reply
                          3
                          • Q Qt embedded developer

                            @KroMignon i can not enable it like that because any change like that not allowed in my device.

                            KroMignonK Offline
                            KroMignonK Offline
                            KroMignon
                            wrote on last edited by KroMignon
                            #25

                            @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

                            i can not enable it like that because any change like that not allowed in my device.

                            As @jsulm already wrote before, replace auto with the corresponding type:

                            for(std::map<int,SqliteManagerBGSync*>::iterator it = sqliteManagerMap::begin(); it != sqliteManagerMap::end(); ++it)
                            {
                            ...
                            }
                            

                            It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

                            J.HilkJ Q 3 Replies Last reply
                            1
                            • KroMignonK KroMignon

                              @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

                              i can not enable it like that because any change like that not allowed in my device.

                              As @jsulm already wrote before, replace auto with the corresponding type:

                              for(std::map<int,SqliteManagerBGSync*>::iterator it = sqliteManagerMap::begin(); it != sqliteManagerMap::end(); ++it)
                              {
                              ...
                              }
                              
                              J.HilkJ Offline
                              J.HilkJ Offline
                              J.Hilk
                              Moderators
                              wrote on last edited by J.Hilk
                              #26

                              @KroMignon IIRC range based for loops is a c++11 feature in itself 🤔

                              never mind, I think need a break!


                              Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                              Q: What's that?
                              A: It's blue light.
                              Q: What does it do?
                              A: It turns blue.

                              KroMignonK 1 Reply Last reply
                              0
                              • J.HilkJ J.Hilk

                                @KroMignon IIRC range based for loops is a c++11 feature in itself 🤔

                                never mind, I think need a break!

                                KroMignonK Offline
                                KroMignonK Offline
                                KroMignon
                                wrote on last edited by
                                #27

                                @J-Hilk said in Deallocate memory to singleton class which access database ?:

                                IIRC range based for loops is a c++11 feature in itself 🤔

                                Are you sure? I don't believe that std::map<>::iterator support is comming with C++11.

                                It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

                                jsulmJ 1 Reply Last reply
                                0
                                • KroMignonK KroMignon

                                  @J-Hilk said in Deallocate memory to singleton class which access database ?:

                                  IIRC range based for loops is a c++11 feature in itself 🤔

                                  Are you sure? I don't believe that std::map<>::iterator support is comming with C++11.

                                  jsulmJ Offline
                                  jsulmJ Offline
                                  jsulm
                                  Lifetime Qt Champion
                                  wrote on last edited by
                                  #28

                                  @KroMignon I think @J-Hilk misunderstood your code: you are not using range based loop

                                  https://forum.qt.io/topic/113070/qt-code-of-conduct

                                  1 Reply Last reply
                                  1
                                  • KroMignonK KroMignon

                                    @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

                                    i can not enable it like that because any change like that not allowed in my device.

                                    As @jsulm already wrote before, replace auto with the corresponding type:

                                    for(std::map<int,SqliteManagerBGSync*>::iterator it = sqliteManagerMap::begin(); it != sqliteManagerMap::end(); ++it)
                                    {
                                    ...
                                    }
                                    
                                    Q Offline
                                    Q Offline
                                    Qt embedded developer
                                    wrote on last edited by Qt embedded developer
                                    #29

                                    @KroMignon Here inside for loop i need to write

                                    for(std::map<int,SqliteManagerBGSync*>::iterator it = sqliteManagerMap::begin(); it != sqliteManagerMap::end(); ++it)
                                    {
                                    delete it;
                                    }
                                    
                                    

                                    or what i need to write to deallocate memory ?

                                    jsulmJ KroMignonK 2 Replies Last reply
                                    0
                                    • Q Qt embedded developer

                                      @KroMignon Here inside for loop i need to write

                                      for(std::map<int,SqliteManagerBGSync*>::iterator it = sqliteManagerMap::begin(); it != sqliteManagerMap::end(); ++it)
                                      {
                                      delete it;
                                      }
                                      
                                      

                                      or what i need to write to deallocate memory ?

                                      jsulmJ Offline
                                      jsulmJ Offline
                                      jsulm
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #30

                                      @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

                                      delete it;

                                      delete it->second;

                                      of course

                                      https://forum.qt.io/topic/113070/qt-code-of-conduct

                                      1 Reply Last reply
                                      1
                                      • Q Qt embedded developer

                                        @KroMignon Here inside for loop i need to write

                                        for(std::map<int,SqliteManagerBGSync*>::iterator it = sqliteManagerMap::begin(); it != sqliteManagerMap::end(); ++it)
                                        {
                                        delete it;
                                        }
                                        
                                        

                                        or what i need to write to deallocate memory ?

                                        KroMignonK Offline
                                        KroMignonK Offline
                                        KroMignon
                                        wrote on last edited by KroMignon
                                        #31

                                        @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

                                        or what i need to write to deallocate ?

                                        Please, take time to read std::map<> documentation.
                                        You are using a map iterator, so it is a container object which gives you access to key and value.

                                        delete it do not make sense!

                                        You want to delete the pointer hold in the value part: delete it->second

                                        It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

                                        Q 1 Reply Last reply
                                        3
                                        • KroMignonK KroMignon

                                          @Qt-embedded-developer said in Deallocate memory to singleton class which access database ?:

                                          or what i need to write to deallocate ?

                                          Please, take time to read std::map<> documentation.
                                          You are using a map iterator, so it is a container object which gives you access to key and value.

                                          delete it do not make sense!

                                          You want to delete the pointer hold in the value part: delete it->second

                                          Q Offline
                                          Q Offline
                                          Qt embedded developer
                                          wrote on last edited by Qt embedded developer
                                          #32
                                          This post is deleted!
                                          1 Reply Last reply
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