Date: Sun, 20 Feb 2005 00:07:33 +0100 From: Gert Cuykens <gert.cuykens@gmail.com> To: "Chad Leigh -- Shire. Net LLC" <chad@shire.net> Cc: freebsd-questions@freebsd.org Subject: Re: c++ Message-ID: <ef60af0905021915074e5d2929@mail.gmail.com> In-Reply-To: <5b8472dd5925a0b0b59f15cd9f8e15f3@shire.net> References: <ef60af09050219015116024f83@mail.gmail.com> <5b8472dd5925a0b0b59f15cd9f8e15f3@shire.net>
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On Sat, 19 Feb 2005 02:57:53 -0700, Chad Leigh -- Shire. Net LLC <chad@shire.net> wrote: >=20 > On Feb 19, 2005, at 2:51 AM, Gert Cuykens wrote: >=20 > > On Thu, 17 Feb 2005 13:17:51 +0100, Hubert Soko=C5=82owski > > <h.sokolowski@wsisiz.edu.pl> wrote: > >> On Thu, 17 Feb 2005 13:05:43 +0100 > >> Gert Cuykens <gert.cuykens@gmail.com> wrote: > >> > >>> static void callback( GtkWidget *widget, gpointer data ){ > >>> g_print ("Hello again - %s was pressed\n", (gchar *) data); > >>> } > >>> > >>> why do they put () around gchar ? > >>> why can it not be gchar *data ? > >> > >> You should learn some more about programming in C before you start > >> writing GTK apps. > >> > >> hs > > > > Does anybody want to explain what the () thingies are around gchar * ? > > >=20 > It is a typecast -- coercing "data" to be of type (gchar *) to the > compiler when matching parameter types at compiler time. >=20 > Chad >=20 lol :) I wish you could see the expression on my face while reading it :)= =20 Why can i not do this ? g_print ("Hello again - %s was pressed\n", gchar *data); or this gchar *data; g_print ("Hello again - %s was pressed\n", *data); or this gchar *data; g_print ("Hello again - %s was pressed\n", data); What does coercing mean ? Why does the compiler have to match parameters ? PS what is the difference between ? A=3D*data A=3Ddata A=3D&data
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