What is this thing in my STRUCT?

Dr_Firmware

Hi Qt's,

I did the search and even reread chapter 8 of "The C++ Programming Language".

So I am trying to get up to speed on Qt and C++ and came across this little gem in an example:

//Structure for the response to the QUERY_EXTENDED_INFO command
    union ExtendedQueryInfo
    {
        unsigned char command;
        struct
        {
            unsigned char command;
            uint16_t bootloaderVersion;
            uint16_t applicationVersion;
            uint32_t signatureAddress;
            uint16_t signatureValue;
            uint32_t erasePageSize;
            unsigned char config1LMask;
            unsigned char config1HMask;
            unsigned char config2LMask;
            unsigned char config2HMask;
            unsigned char config3LMask;
            unsigned char config3HMask;
            unsigned char config4LMask;
            unsigned char config4HMask;
            unsigned char config5LMask;
            unsigned char config5HMask;
            unsigned char config6LMask;
            unsigned char config6HMask;
            unsigned char config7LMask;
            unsigned char config7HMask;
            unsigned char pad[USB_PACKET_SIZE_WITH_REPORT_ID - 29];
        }PIC18;
        struct
        {
            unsigned char command;
            uint16_t bootloaderVersion;
            uint16_t applicationVersion;
            uint32_t signatureAddress;
            uint16_t signatureValue;
            uint32_t erasePageSize;
            uint16_t configxxMask...
            unsigned char pad[USB_PACKET_SIZE_WITH_REPORT_ID - XX];
        }PIC24;
    };

Can someone explain the purpose of the PIC18 and PIC24 at the end of those 2 struct's?

Regards,

Chris

? Offline

 struct
         {
             unsigned char command;
             uint16_t bootloaderVersion;
             uint16_t applicationVersion;
             uint32_t signatureAddress;
             uint16_t signatureValue;
             uint32_t erasePageSize;
             uint16_t configxxMask...
             unsigned char pad[USB_PACKET_SIZE_WITH_REPORT_ID - XX];
         } PIC24;

This defines an anonymous structure and declares a variable of this type named "PIC24" .

SGaist

Hi and welcome to devnet,

That's rather a general C/C++ question unrelated to Qt but anyway, here you have the complete explanation

Dr_Firmware

@SGaist thanks for the warm reception.

Thanks for the link. I have written firmware in C and some desktop apps in C#. And since I'm no expert in either, moving to C++ in Qt it becomes a little unclear what code related items are strictly C++ and which are part of the Qt IDE.

I hope to get it sorted without committing to many forum faux pas.

Best regards,

Chris

SGaist

Don't worry for that, you won't be eaten ;)

I've forgotten that there's also the C++ Guru sub forum when you have questions that are more C++ oriented

Happy coding !