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|    comp.lang.c++.moderated    |    Moderated discussion of C++ superhackery    |    33,346 messages    |
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|    Message 32,565 of 33,346    |
|    Wil Evers to kiran    |
|    Re: Cannot convert =?iso8859-7?b?oWludCB    |
|    25 Sep 12 22:04:13    |
      From: bouncer@dev.null              kiran wrote:              > Here is a code snippet:       > =============       > int **ptr;       > int intArr[3][5];       > ptr = intArr;       > =============       >       > This gives the error on g++ compiler:       > error: cannot convert Ħint [3][5]˘ to Ħint**˘ in assignment       >       > I have tried other variants as well, like       > int const **ptr = intArr;       > and       > ptr = &intArr[0];       >       > I still got the same error. Can anyone explain the reason here.              The declaration               int intArr[3][5];              declares intArr to be an array of 3 arrays of 5 ints. The language's       decay rule says that the name of this array can be implictly converted       to a pointer to its first element. Thus, we can write:               int (*p1)[5] = intArr;              Note that p1 is not a pointer to a pointer to an int; it is a pointer to       an array of 5 ints, pointing to intArr[0].              In contrast, if we write:               int **p2;              We're saying that p2 points to a pointer to an int. If it were legal to       write               int **p2 = intArr;              then where is the pointer that p2 points to? There is none, which is       why this conversion has to be illegal.              HTH,              - Wil                     --        [ See http://www.gotw.ca/resources/clcm.htm for info about ]        [ comp.lang.c++.moderated. First time posters: Do this! ]              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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