C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Pointer to function Typedefs          C++Talk.NET Forum Index -> C++ Language (Moderated) View previous topic :: View next topic   Author Message Guest Posted: Fri Feb 10, 2006 2:06 pm    Post subject: Pointer to function Typedefs I have seen lot of definition like the one below in code typedef void (*func_cback) (arg1, arg2) I need to know what this means in layman terms Thanks in Advance KIRAN [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Ulrich Eckhardt Guest Posted: Fri Feb 10, 2006 3:06 pm    Post subject: Re: Pointer to function Typedefs kirantsbe (AT) gmail (DOT) com wrote: Quote: I have seen lot of definition like the one below in code typedef void (*func_cback) (arg1, arg2) I need to know what this means in layman terms Firstly, you simply read this from the inside out and from left to right. - func_cback func_cback is - (*func_cback) func_cback is a pointer - (*func_cback)(arg1, arg2) func_cback is a pointer to a function taking an arg1 and an arg2 - void (*func_cback)(arg1, arg2) func_cback is a pointer to a function taking an arg1 and an arg2 and returning nothing The typedef in front now makes this not the definition of a function pointer but a typedef for a function pointer. Secondly, the IMHO easier syntax is to use a function typedef instead of a function pointer typedef: #if 0 typedef void (*func_cback) (arg1, arg2); funct_cback cb = &some_function; #else typedef void func_cback(arg1, arg2); func_cback* cb = &some_function; #endif This way makes it more obvious that 'cb' is a pointer here. Uli [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Seungbeom Kim Guest Posted: Fri Feb 17, 2006 4:06 pm    Post subject: Re: Pointer to function Typedefs Ulrich Eckhardt wrote: Quote: Secondly, the IMHO easier syntax is to use a function typedef instead of a function pointer typedef: #if 0 typedef void (*func_cback) (arg1, arg2); funct_cback cb = &some_function; #else typedef void func_cback(arg1, arg2); func_cback* cb = &some_function; #endif This way makes it more obvious that 'cb' is a pointer here. Unfortunately, this doesn't work with pointer to member types: struct S { void f(); }; // OK typedef void (S::*pft)(); pft pf = &S::f; // Error typedef void (S::ft)(); ft* pf = &S::f; I used to like the idea of using a function typedef instead of a function pointer typedef myself, but now with pointers to members, that spoils the consistency and I cannot make up my mind. :( -- Seungbeom Kim [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C++ Language (Moderated) All times are GMT Page 1 of 1   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.