CODEWITHSUNDEEP
c++pointerssyntaxcompiler-errorsdynamic-allocation
msantiago
msantiago

Reputation: 346

error: request for member (maybe you meant to use '->' ?) while using '->' already

Is there an easy explanation for what this error means?

error: request for member 'Attributes' in '* printerInfo', which is of pointer type 'PPRINTER_INFO_2 {aka _PRINTER_INFO_2A*}' (maybe you meant to use '->' ?)

PPRINTER_INFO_2* printerInfo = NULL;

    void ChangedPrinter()
    {
       ...
       DWORD attributesPrinterInfo;

       printerInfo = (PPRINTER_INFO_2*) malloc(bufferSize);

       attributesPrinterInfo = printerInfo->Attributes; // error

       free(printerInfo);
    }

What am I doing wrong???

Upvotes: 3

Views: 20561

Answers (2)

indev
indev

Reputation: 165

for Cpp, See this https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91138

Suggesting -> isn't helpful when it already uses it. The right fix-it is to suggest (*pp)->member

Upvotes: 0

LihO
LihO

Reputation: 42133

PRINTER_INFO_2 structure is defined as:

typedef struct _PRINTER_INFO_2 {
  // ...
} PRINTER_INFO_2, *PPRINTER_INFO_2;

so PPRINTER_INFO_2 is pointer to PRINTER_INFO_2. When you do

printerInfo = (PPRINTER_INFO_2*) malloc(bufferSize);

printerInfo actually becomes a pointer to pointer to PRINTER_INFO_2. I'm not sure whether this was an intention or just a mistake, but if it's intended to be PPRINTER_INFO_2* then proper usage is:

(*printerInfo)->Attributes

Upvotes: 9

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