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Can someone please explain this function pointer declaration:

float (* getptr (char opcode) ) (int, int);

I'm confused by the syntax - I have not seen a function pointer with
the extra parameter "char opcode" in the parentheses.

Thanks,
fred.

In article < om>,
<> wrote:

>Can someone please explain this function pointer declaration:
>
>float (* getptr (char opcode) ) (int, int);

It declares getptr as a function taking a char argument called opcode
and returning a pointer to a function taking two integers and
returning a float.

>I'm confused by the syntax - I have not seen a function pointer with
>the extra parameter "char opcode" in the parentheses.

That's not an "extra parameter" - that's the ordinary part of the
declaration! The

float (* ... ) (int, int)

wrapped around it is describing the return type.

-- Richard

--
"Consideration shall be given to the need for as many as 32 characters
in some alphabets" - X3.4, 1963.

writes:

> Can someone please explain this function pointer declaration:
>
> float (* getptr (char opcode) ) (int, int);
>
> I'm confused by the syntax - I have not seen a function pointer with
> the extra parameter "char opcode" in the parentheses.

This is not a declaration of a function pointer. It is a
declaration of a function named "getptr" taking a single
parameter of type char and returning a pointer to a function
taking two int parameters and returning a float.
--
Comp-sci PhD expected before end of 2007
Seeking industrial or academic position *outside California* in 2008

On May 10, 9:33 am, Ben Pfaff <b...@cs.stanford.edu> wrote:
> fred.zak...@gmail.com writes:
> > Can someone please explain this function pointer declaration:
>
> > float (* getptr (char opcode) ) (int, int);
>
> > I'm confused by the syntax - I have not seen a function pointer with
> > the extra parameter "char opcode" in the parentheses.
>
> This is not a declaration of a function pointer. It is a
> declaration of a function named "getptr" taking a single
> parameter of type char and returning a pointer to a function
> taking two int parameters and returning a float.
> --
> Comp-sci PhD expected before end of 2007
> Seeking industrial or academic position *outside California* in 2008


Thanks very much for the answers guys!
fred.

wrote:
> Can someone please explain this function pointer declaration:
>
> float (* getptr (char opcode) ) (int, int);
>
> I'm confused by the syntax - I have not seen a function pointer with
> the extra parameter "char opcode" in the parentheses.
>
Find a copy of "cdecl" and run it against this signature. Most versions
of the utility will describe, in English, what is going on.

I get "declare getptr as function that expects (opcode as char)
returning pointer to function that expects (int, int) returning float;"
--
clvrmnky

Direct replies will be blacklisted. Replace "spamtrap" with my name to
contact me directly.

On May 10, 10:15 am, Clever Monkey <spamt...@clevermonkey.org.INVALID>
wrote:
> fred.zak...@gmail.com wrote:
> > Can someone please explain this function pointer declaration:
>
> > float (* getptr (char opcode) ) (int, int);
>
> > I'm confused by the syntax - I have not seen a function pointer with
> > the extra parameter "char opcode" in the parentheses.
>
> Find a copy of "cdecl" and run it against this signature. Most versions
> of the utility will describe, in English, what is going on.
>
> I get "declare getptr as function that expects (opcode as char)
> returning pointer to function that expects (int, int) returning float;"
> --
> clvrmnky
>
> Direct replies will be blacklisted. Replace "spamtrap" with my name to
> contact me directly.

I tried Cdecl, but all I get is "parse error"!
fred

wrote:
> On May 10, 10:15 am, Clever Monkey <spamt...@clevermonkey.org.INVALID>
> wrote:
>> fred.zak...@gmail.com wrote:
>>> Can someone please explain this function pointer declaration:
>>> float (* getptr (char opcode) ) (int, int);
>>> I'm confused by the syntax - I have not seen a function pointer with
>>> the extra parameter "char opcode" in the parentheses.
>> Find a copy of "cdecl" and run it against this signature. Most versions
>> of the utility will describe, in English, what is going on.
>>
>> I get "declare getptr as function that expects (opcode as char)
>> returning pointer to function that expects (int, int) returning float;"
>> --
>> clvrmnky
>>
>> Direct replies will be blacklisted. Replace "spamtrap" with my name to
>> contact me directly.
>
> I tried Cdecl, but all I get is "parse error"!
> fred
>
Check the documentation. My cdecl needs to read the entries from a
file, and they must be "correct" and have a trailing ";"
--
clvrmnky <private.php?do=newpm&u=>

Direct replies will be blacklisted. Replace "spamtrap" with my name to
contact me directly.

Clever Monkey wrote:

> wrote:
> > Can someone please explain this function pointer declaration:
> >
> > float (* getptr (char opcode) ) (int, int);
> >
> > I'm confused by the syntax - I have not seen a function pointer with
> > the extra parameter "char opcode" in the parentheses.
> >
> Find a copy of "cdecl" and run it against this signature. Most
> versions of the utility will describe, in English, what is going on.
>
> I get "declare getptr as function that expects (opcode as char)
> returning pointer to function that expects (int, int) returning
> float;"

Has anybody seen an online cdecl? One where you could paste a
declaration into a web form and get back the result?

It seems like the sort of thing somebody might do, like all those
online calculators for various things, but I didn't have any luck
searching for one.



Brian

CBFalconer <> writes:
> Clever Monkey wrote:
>> wrote:
>>
>>> Can someone please explain this function pointer declaration:
>>>
>>> float (* getptr (char opcode) ) (int, int);
>>>
>>> I'm confused by the syntax - I have not seen a function pointer
>>> with the extra parameter "char opcode" in the parentheses.
>>
>> Find a copy of "cdecl" and run it against this signature. Most
>> versions of the utility will describe, in English, what is going
>> on.
>>
>> I get "declare getptr as function that expects (opcode as char)
>> returning pointer to function that expects (int, int) returning
>> float;"
>
> I get 'parse error'.

So do I (actually "syntax error", not "parse error"), but the error
message goes away if I delete the parameter name "opcode":

% cdecl -V
Version:
@(#)cdecl.c 2.5 1/15/96
@(#)cdgram.y 2.2 3/30/88
@(#)cdlex.l 2.2 3/30/88
% cdecl
Type `help' or `?' for help
cdecl> explain float (* getptr (char opcode) ) (int, int)
syntax error
cdecl> explain float (* getptr (char) ) (int, int)
declare getptr as function (char) returning pointer to function (int, int) returning float
cdecl>

Perhaps different versions of cdecl handle this differently.

--
Keith Thompson (The_Other_Keith) kst- <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

Am Thu, 10 May 2007 09:31:19 -0700 schrieb fred.zakity:

> On May 10, 10:15 am, Clever Monkey <spamt...@clevermonkey.org.INVALID>
> wrote:
>> fred.zak...@gmail.com wrote:
>> > Can someone please explain this function pointer declaration:
>>
>> > float (* getptr (char opcode) ) (int, int);
<snip>
>> Find a copy of "cdecl" and run it against this signature.
<snip>
> I tried Cdecl, but all I get is "parse error"!
> fred

Leave out the "opcode":

cdecl> explain float (*getptr(char))(int, int)

and it will work.

hth,
Wolfram