explicit cast to malloc()

[mohi]

hello everyone ,
as i have noted a lot many times it has been mentioned that we shudn't
cast pointers returned by malloc()
i mean
its been said that use
node * nod=malloc(sizeof(node));

instead of

node * nod=(node *) malloc( sizeof(node));

but when i use the upper way my gcc compiler shows error like

invalid conversion from void* to node*

whats the matter ?

pls help
thank you
mohan

[Eric Sosman]

mohi wrote:

hello everyone ,
as i have noted a lot many times it has been mentioned that we shudn't
cast pointers returned by malloc()
i mean
its been said that use
node * nod=malloc(sizeof(node));

instead of

node * nod=(node *) malloc( sizeof(node));

but when i use the upper way my gcc compiler shows error like

invalid conversion from void* to node*

whats the matter ?

You're compiling C++, not C. The comp.lang.c++ newsgroup
is just down the hall to your left; I hear they're planning to
have a party as soon as they find the template.

--
Er*********@sun.com

[William Pursell]

On 25 Jul, 20:46, mohi <[e-mail]:

as i have noted a lot many times it has been mentioned that we shudn't
cast pointers returned by malloc()
i mean
its been said that use
node * nod=malloc(sizeof(node));

instead of

node * nod=(node *) malloc( sizeof(node));

but when i use the upper way my gcc compiler shows error like

invalid conversion from void* to node*

whats the *matter ?

Most likely you are invoking gcc as a c++ compiler.

[Keith Thompson]

mohi <mo**********@gmail.comwrites:

as i have noted a lot many times it has been mentioned that we shudn't
cast pointers returned by malloc()
i mean
its been said that use
node * nod=malloc(sizeof(node));

instead of

node * nod=(node *) malloc( sizeof(node));

but when i use the upper way my gcc compiler shows error like

invalid conversion from void* to node*

whats the matter ?

Does it show an error *like* "invalid conversion from void* to node*",
or does it show that exact error?

I might expect to see an error message about converting from int to
node* if you forgot the mandatory "#include <stdio.h>".

If that doesn't help, read question 7.6 of the comp.lang.c FAQ,
<http://www.c-faq.com/>, and in the future please check the FAQ before
posting. If that doesn't help, read the rest of section 7, and
perhaps the entire FAQ. And if *that* doesn't help, feel free to post
again -- but *please* copy-and-paste your actual complete program and
the exact error message.

--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[David Resnick]

On Jul 25, 4:10*pm, Keith Thompson <[e-mail]:

mohi <[e-mail]:

as i have noted a lot many times it has been mentioned that we shudn't
cast pointers returned by malloc()
i mean
its been said that use
node * nod=malloc(sizeof(node));

instead of

node * nod=(node *) malloc( sizeof(node));

but when i use the upper way my gcc compiler shows error like

invalid conversion from void* to node*

whats the *matter ?

Does it show an error *like* "invalid conversion from void* to node*",
or does it show that exact error?

I might expect to see an error message about converting from int to
node* if you forgot the mandatory "#include <stdio.h>".

You mean <stdlib.h>...

-David

[mohi]

On Jul 26, 1:14 am, David Resnick <[e-mail]:

On Jul 25, 4:10 pm, Keith Thompson <[e-mail]:

mohi <[e-mail]:

as i have noted a lot many times it has been mentioned that we shudn't
cast pointers returned by malloc()
i mean
its been said that use
node * nod=malloc(sizeof(node));

instead of

node * nod=(node *) malloc( sizeof(node));

but when i use the upper way my gcc compiler shows error like

invalid conversion from void* to node*

whats the matter ?

Does it show an error *like* "invalid conversion from void* to node*",
or does it show that exact error?

I might expect to see an error message about converting from int to
node* if you forgot the mandatory "#include <stdio.h>".

You mean <stdlib.h>...

-David

sorry guys im really sorry
i did compile it with g++
it becomes so confusing when u have to use both c and c++
is there a better way of dealing with this confusion
:)
mohan

[Eric Sosman]

mohi wrote:

[...]
it becomes so confusing when u have to use both c and c++
is there a better way of dealing with this confusion

Sure:

(setq use-C nil
use-C++ nil
use-lisp exclusively
tongue-in-cheek t)

--
Er*********@sun.com

[Keith Thompson]

David Resnick <ln********@gmail.comwrites:

On Jul 25, 4:10*pm, Keith Thompson <[e-mail]:

[...]

>I might expect to see an error message about converting from int to
node* if you forgot the mandatory "#include <stdio.h>".

You mean <stdlib.h>...

Yes, thanks.

--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[CBFalconer]

mohi wrote:

>
as i have noted a lot many times it has been mentioned that we
shudn't cast pointers returned by malloc(). i mean its been
said that use: node * nod=malloc(sizeof(node));
instead of: node * nod=(node *) malloc( sizeof(node));

but when i use the upper way my gcc compiler shows error like
invalid conversion from void* to node*

whats the matter ?

You are using a C++ compiler, not a C compiler. Probably because
you have misnamed the source file, which should be of type .c
(lower case).

--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: <http://cbfalconer.home.att.net>
Try the download section.

[Greg Comeau]

In article <84**********************************@s21g2000prm. googlegroups.com>,
mohi <mo**********@gmail.comwrote:

>as i have noted a lot many times it has been mentioned that we shudn't
cast pointers returned by malloc()
i mean
its been said that use
node * nod=malloc(sizeof(node));

instead of

node * nod=(node *) malloc( sizeof(node));

but when i use the upper way my gcc compiler shows error like

invalid conversion from void* to node*

Does it literally say void *, or does it say int?
If it literally says void * you're probably compiling in C++
mode not in C mode. If it says int, then, you're probably
not #include'ing the right header for malloc, that is, stdlib.h
--
Greg Comeau / 4.3.10.1 with C++0xisms now in beta!
Comeau C/C++ ONLINE == http://www.comeaucomputing.com/tryitout
World Class Compilers: Breathtaking C++, Amazing C99, Fabulous C90.
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