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Otto Lind
Guest
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 Posted: Fri Mar 05, 2004 7:43 pm Post subject: static_cast and globally scoped types. |
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The following program shows the problem:
#include <stdio.h>
namespace x
{
enum L { One = 1, Two = 2 };
namespace x
{
enum L { Three = 3, Four = 4 };
void foo(long mylong)
{
: ::L l;
//
// This fails to compile due to syntax error
//
l = static_cast<:::L>(mylong);
//
// This (correctly) fails to compile since it uses
// wrong enum.
//
l = static_cast<x::L>(mylong);
}
}
}
int main()
{
long l = 1;
x:::foo(l);
return 0;
}
When compiled with g++ (3.3.2) and Sun's CC (5.5 Patch 113817-03), both
report a syntax error when using a globally scoped type:
% CC foo.cpp
"foo.cpp", line 19: Error: "<" expected instead of "<:".
"foo.cpp", line 19: Error: Type name expected instead of "<:".
"foo.cpp", line 19: Error: Expected an expression.
"foo.cpp", line 24: Error: Cannot assign x:::L to x::L.
% g++ foo.cpp
foo.cpp: In function `void x:::foo(long int)':
foo.cpp:19: error: parse error before `[' token
foo.cpp:24: error: cannot convert `x:::L' to `x::L' in assignment
I had assumed that globally scoped types could be used in static_cast<>,
specifically to resolve scope issues. Is this a bug in the compiler? If
not, what would be the best workaround?
Otto
--
Otto Lind Kabira Technologies (http://www.kabira.com)
[email]otto (AT) olcs (DOT) com[/email] 12193 285th street, Lindstrom, MN 55045
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Leor Zolman
Guest
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| Posted: Fri Mar 05, 2004 8:08 pm Post subject: Re: static_cast and globally scoped types. |
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On 05 Mar 2004 19:43:14 GMT, [email]otto (AT) olcs (DOT) com[/email] (Otto Lind) wrote:
| Quote: | The following program shows the problem:
#include <stdio.h
namespace x
{
enum L { One = 1, Two = 2 };
namespace x
{
enum L { Three = 3, Four = 4 };
void foo(long mylong)
{
:::L l;
//
// This fails to compile due to syntax error
//
l = static_cast<:::L>(mylong);
|
Looks like <: is a diagraph equivalent of '[', believe it or not (I didn't
know that...). Put a space after the <.
| Quote: | //
// This (correctly) fails to compile since it uses
// wrong enum.
//
l = static_cast
right. |
-leor
Leor Zolman
BD Software
[email]leor (AT) bdsoft (DOT) com[/email]
www.bdsoft.com -- On-Site Training in C/C++, Java, Perl & Unix
C++ users: Download BD Software's free STL Error Message
Decryptor at www.bdsoft.com/tools/stlfilt.html
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Sam Dennis
Guest
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| Posted: Fri Mar 05, 2004 8:14 pm Post subject: Re: static_cast and globally scoped types. |
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Otto Lind wrote:
| Quote: | l = static_cast<:::L>(mylong);
When compiled with g++ (3.3.2) and Sun's CC (5.5 Patch 113817-03), both
report a syntax error when using a globally scoped type:
"foo.cpp", line 19: Error: "<" expected instead of "<:".
|
Your problem is not the same as the problem you think it is; `<:' is the
digraph for `[' (in C, at least, and I would think that this is the same
in C++), so you do, indeed, have a syntax error.
Try this, instead:
l = static_cast< :::L >(mylong);
--
++acr@,ka"
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Leor Zolman
Guest
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| Posted: Fri Mar 05, 2004 8:15 pm Post subject: Re: static_cast and globally scoped types. |
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On Fri, 05 Mar 2004 20:08:02 GMT, Leor Zolman <leor (AT) bdsoft (DOT) com> wrote:
| Quote: | Looks like <: is a diagraph equivalent of '[', believe it or not (I didn't
know that...). Put a space after the <.
And yes, I /do/ know how to spell "digraph". That was Freudian slip of the |
fingers.
-leor
Leor Zolman
BD Software
[email]leor (AT) bdsoft (DOT) com[/email]
www.bdsoft.com -- On-Site Training in C/C++, Java, Perl & Unix
C++ users: Download BD Software's free STL Error Message
Decryptor at www.bdsoft.com/tools/stlfilt.html
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jacob navia
Guest
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| Posted: Sat Mar 06, 2004 9:28 am Post subject: Re: static_cast and globally scoped types. |
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"Sam Dennis" <sam (AT) malfunction (DOT) screaming.net> a écrit dans le message de
news:slrnc4hnsj.teh.sam (AT) ID-227112 (DOT) user.uni-berlin.de...
| Quote: | Otto Lind wrote:
l = static_cast<:::L>(mylong);
When compiled with g++ (3.3.2) and Sun's CC (5.5 Patch 113817-03), both
report a syntax error when using a globally scoped type:
"foo.cpp", line 19: Error: "<" expected instead of "<:".
Your problem is not the same as the problem you think it is; `<:' is the
digraph for `[' (in C, at least, and I would think that this is the same
in C++), so you do, indeed, have a syntax error.
Try this, instead:
l = static_cast< :::L >(mylong);
--
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I have proposed in comp.std.c that WE FORGET this digraph/trigraph
nonsense...
I can't understand that C++ needs to be bug compatible with C.
How many "incredible" bugs we will endure?
In C this is less of a problem than in C++, where <: is much more common!
jacob
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