Why doesn't nothrow work?

[Dustan]

This is the biggie that has been keeping me from even trying to use C+
+ for more than about 10 seconds: it doesn't work. I've been able to
get java and (of course) python programs to compile and run, but not C+
+.

I copied a program from http://www.cplusplus.com/doc/tutorial/dynamic.html
(if that's a bad place to go for a tutorial, feel free to direct me
elsewhere), and the following line gets an error:

p= new (nothrow) int[i];

Here are the errors I get (all on line 11, the one above):
`nothrow' undeclared (first use this function)
(Each undeclared identifier is reported only once
for each function it appears in.)
confused by earlier errors, bailing out

It seems odd to me that it's calling 'nothrow' a function; is (XXX)
really valid functional notation in C++? I thought that syntax was
reserved for casts.

I'm using Bloodshed Dev-C++ Version 4, on Microsoft Windows XP Version
5.1.2600. Any ideas as to what my problem might be?

[Victor Bazarov]

Dustan wrote:

This is the biggie that has been keeping me from even trying to use C+
+ for more than about 10 seconds: it doesn't work. I've been able to
get java and (of course) python programs to compile and run, but not
C+ +.

I copied a program from
http://www.cplusplus.com/doc/tutorial/dynamic.html (if that's a bad
place to go for a tutorial, feel free to direct me elsewhere), and
the following line gets an error:

p= new (nothrow) int[i];

Have you tried

p = new (std::nothrow) int[i];

?

>
Here are the errors I get (all on line 11, the one above):
`nothrow' undeclared (first use this function)
(Each undeclared identifier is reported only once
for each function it appears in.)
confused by earlier errors, bailing out

It seems odd to me that it's calling 'nothrow' a function; is (XXX)
really valid functional notation in C++? I thought that syntax was
reserved for casts.

I'm using Bloodshed Dev-C++ Version 4, on Microsoft Windows XP Version
5.1.2600. Any ideas as to what my problem might be?

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

[Dustan]

On May 29, 12:02 pm, "Victor Bazarov" <v.Abaza...@com Acast.netwrote:

Dustan wrote:

This is the biggie that has been keeping me from even trying to use C+
+ for more than about 10 seconds: it doesn't work. I've been able to
get java and (of course) python programs to compile and run, but not
C+ +.

I copied a program from
http://www.cplusplus.com/doc/tutorial/dynamic.html(if that's a bad
place to go for a tutorial, feel free to direct me elsewhere), and
the following line gets an error:

p= new (nothrow) int[i];

Have you tried

p = new (std::nothrow) int[i];

?

Thanks for the response.

Yes I had tried that, and no, it didn't work. I didn't get the exact
same error messages, but it conveyed the same problem:
`::nothrow' undeclared (first use here)
confused by earlier errors, bailing out

Here are the errors I get (all on line 11, the one above):
`nothrow' undeclared (first use this function)
(Each undeclared identifier is reported only once
for each function it appears in.)
confused by earlier errors, bailing out

It seems odd to me that it's calling 'nothrow' a function; is (XXX)
really valid functional notation in C++? I thought that syntax was
reserved for casts.

I'm using Bloodshed Dev-C++ Version 4, on Microsoft Windows XP Version
5.1.2600. Any ideas as to what my problem might be?

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

[red floyd]

Dustan wrote:

This is the biggie that has been keeping me from even trying to use C+
+ for more than about 10 seconds: it doesn't work. I've been able to
get java and (of course) python programs to compile and run, but not C+
+.

I copied a program from http://www.cplusplus.com/doc/tutorial/dynamic.html
(if that's a bad place to go for a tutorial, feel free to direct me
elsewhere), and the following line gets an error:

p= new (nothrow) int[i];

Here are the errors I get (all on line 11, the one above):
`nothrow' undeclared (first use this function)
(Each undeclared identifier is reported only once
for each function it appears in.)
confused by earlier errors, bailing out

Did you #include <new>?

[Zeppe]

Dustan wrote:

This is the biggie that has been keeping me from even trying to use C+
+ for more than about 10 seconds: it doesn't work. I've been able to
get java and (of course) python programs to compile and run, but not C+
+.

C++ it's a little bit tricky but when you know how to use it it's very
powerful, more than python or java. It's worth the time ;)

I copied a program from http://www.cplusplus.com/doc/tutorial/dynamic.html
(if that's a bad place to go for a tutorial, feel free to direct me
elsewhere), and the following line gets an error:

I don't know exactly, many tutorials in the net have got slight errors
or imperfections.

>
p= new (nothrow) int[i];

Here are the errors I get (all on line 11, the one above):
`nothrow' undeclared (first use this function)
(Each undeclared identifier is reported only once
for each function it appears in.)
confused by earlier errors, bailing out

It seems odd to me that it's calling 'nothrow' a function; is (XXX)
really valid functional notation in C++? I thought that syntax was
reserved for casts.

Well, it's not. The brackets are just dummy, and then ignored, and the
token is interpreted as a function reference. But those are
technicalities for a learner, in my opinion. You will learn, with the
experience, to do this:

1) read the error: `nothrow' undeclared
2) why is undeclared? it's standard library! so, try std::nothrow
3) error: ‘nothrow’ is not a member of ‘std’... Damn!
4) why it is not? because everything in c++ has to be defined somewhere,
and all the things of the standard library are defined in a header file
5) pick a book, and check out std::nothrow
6) #include <memory>
7) it works!

;)

Regards,

Zeppe

[Dustan]

On May 29, 12:46 pm, Zeppe
<zep_p@.remove. all.this.long.c omment.yahoo.it wrote:

Dustan wrote:

This is the biggie that has been keeping me from even trying to use C+
+ for more than about 10 seconds: it doesn't work. I've been able to
get java and (of course) python programs to compile and run, but not C+
+.

C++ it's a little bit tricky but when you know how to use it it's very
powerful, more than python or java. It's worth the time ;)

Yeah... they say that exact same thing over at c.l.python and
c.l.java. I get the feeling everyone's biased or something. ;)

I copied a program fromhttp://www.cplusplus.c om/doc/tutorial/dynamic.html
(if that's a bad place to go for a tutorial, feel free to direct me
elsewhere), and the following line gets an error:

I don't know exactly, many tutorials in the net have got slight errors
or imperfections.

p= new (nothrow) int[i];

Here are the errors I get (all on line 11, the one above):
`nothrow' undeclared (first use this function)
(Each undeclared identifier is reported only once
for each function it appears in.)
confused by earlier errors, bailing out

It seems odd to me that it's calling 'nothrow' a function; is (XXX)
really valid functional notation in C++? I thought that syntax was
reserved for casts.

Well, it's not. The brackets are just dummy, and then ignored, and the
token is interpreted as a function reference. But those are
technicalities for a learner, in my opinion. You will learn, with the
experience, to do this:

1) read the error: `nothrow' undeclared
2) why is undeclared? it's standard library! so, try std::nothrow
3) error: 'nothrow' is not a member of 'std'... Damn!
4) why it is not? because everything in c++ has to be defined somewhere,
and all the things of the standard library are defined in a header file
5) pick a book, and check out std::nothrow
6) #include <memory>
7) it works!

;)

Regards,

Zeppe

Thanks to red floyd and Zeppe for their responses. Both <newand
<memoryworked , which I must admit is only further confusing for me;
I guess I still have quite a ways to go.

[Victor Bazarov]

Dustan wrote:

[..]
Thanks to red floyd and Zeppe for their responses. Both <newand
<memoryworked , which I must admit is only further confusing for me;

Why is it confusing you? 'nothrow' is a symbol. It needs to be
defined; and it is, in <new>. It is conceivable that <newis
included into <memory(althoug h it doesn't have to be), so when
you include <memory>, you also implicitly include <new(which is
what you actually need for 'nothrow').

It's similar to how 'NULL' is defined pretty much any time you pull
in *any* standard header (probably), while its actual residence is
in <cstddef>, <cstring>, <cstdio>, <ctime>, or <cwchar>. Don't
rely on NULL's definition to exist all the time, do include one of
the required headers for it.

I guess I still have quite a ways to go.

Most of us do, as well.

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

[red floyd]

Dustan wrote:

On May 29, 12:46 pm, Zeppe
<zep_p@.remove. all.this.long.c omment.yahoo.it wrote:

>Dustan wrote:

>>This is the biggie that has been keeping me from even trying to use C+
+ for more than about 10 seconds: it doesn't work. I've been able to
get java and (of course) python programs to compile and run, but not C+
+.

C++ it's a little bit tricky but when you know how to use it it's very
powerful, more than python or java. It's worth the time ;)

Yeah... they say that exact same thing over at c.l.python and
c.l.java. I get the feeling everyone's biased or something. ;)

>>I copied a program fromhttp://www.cplusplus.c om/doc/tutorial/dynamic.html
(if that's a bad place to go for a tutorial, feel free to direct me
elsewhere), and the following line gets an error:

I don't know exactly, many tutorials in the net have got slight errors
or imperfections.

>> p= new (nothrow) int[i];
Here are the errors I get (all on line 11, the one above):
`nothrow' undeclared (first use this function)
(Each undeclared identifier is reported only once
for each function it appears in.)
confused by earlier errors, bailing out
It seems odd to me that it's calling 'nothrow' a function; is (XXX)
really valid functional notation in C++? I thought that syntax was
reserved for casts.

Well, it's not. The brackets are just dummy, and then ignored, and the
token is interpreted as a function reference. But those are
technicaliti es for a learner, in my opinion. You will learn, with the
experience, to do this:

1) read the error: `nothrow' undeclared
2) why is undeclared? it's standard library! so, try std::nothrow
3) error: 'nothrow' is not a member of 'std'... Damn!
4) why it is not? because everything in c++ has to be defined somewhere,
and all the things of the standard library are defined in a header file
5) pick a book, and check out std::nothrow
6) #include <memory>
7) it works!

;)

Regards,

Zeppe

Thanks to red floyd and Zeppe for their responses. Both <newand
<memoryworked , which I must admit is only further confusing for me;
I guess I still have quite a ways to go.

#include <memoryworkin g is mere coincidence. Your implementation' s
version of <memoryreferenc es <new>. Per the Standard 20.4, <memory>
does not define nothrow. It's defined in <newper 18.4/1.

[Zeppe]

red floyd wrote:

Dustan wrote:

>Thanks to red floyd and Zeppe for their responses. Both <newand
<memoryworke d, which I must admit is only further confusing for me;
I guess I still have quite a ways to go.

#include <memoryworkin g is mere coincidence. Your implementation' s
version of <memoryreferenc es <new>. Per the Standard 20.4, <memory>
does not define nothrow. It's defined in <newper 18.4/1.

Citing the standard, I guess, is to simplify the things to the beginner,
isn't it? Anyway, you caught me, I didn't really checked up in the book ^^

Regards,

Zeppe

[red floyd]

Zeppe wrote:

red floyd wrote:

>Dustan wrote:

>>Thanks to red floyd and Zeppe for their responses. Both <newand
<memoryworked , which I must admit is only further confusing for me;
I guess I still have quite a ways to go.

#include <memoryworkin g is mere coincidence. Your implementation' s
version of <memoryreferenc es <new>. Per the Standard 20.4, <memory>
does not define nothrow. It's defined in <newper 18.4/1.

Citing the standard, I guess, is to simplify the things to the beginner,
isn't it? Anyway, you caught me, I didn't really checked up in the book ^^

No, it's more to explain *why* #include <memoryis the wrong answer.
When in doubt, "because the Standard says so", is a good answer.