473,888 Members | 2,172 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

enum fails with using declaration

As I understand it, loaded statement, a using declaration should be all I
need to see an enum from within a namespace. The below code works fine with
class, struct, and union. What gives? As the code says, if I employ the
using directive, I'm ok.

/* built with Visual C++ 6, SP 5 */
namespace Traffic
{
enum Light { red, yellow, green };
}

int main( void )
{
/*using namespace Traffic; /* using directive. OK */
using Traffic::Light; /* using declaration. error C2065: 'red' :
undeclared identifier */

Light broken = red;
return broken;
}

Nov 13 '05 #1
3 3244
"Marshall Mills" <Mr************ ********@Yahoo. com> writes:
As I understand it, loaded statement, a using declaration should be all I
need to see an enum from within a namespace.


C doesn't have using declarations. Please don't ask C++
questions in comp.lang.c.
Nov 13 '05 #2
Marshall Mills wrote:
As I understand it, loaded statement, a using declaration should be all I
need to see an enum from within a namespace. The below code works fine
with
class, struct, and union. What gives?


Please keep comp.lang.c out of this one. Thanks. :-)

--
Richard Heathfield : bi****@eton.pow ernet.co.uk
"Usenet is a strange place." - Dennis M Ritchie, 29 July 1999.
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
K&R answers, C books, etc: http://users.powernet.co.uk/eton
Nov 13 '05 #3
Marshall Mills wrote:
As I understand it, loaded statement, a using declaration should be all I
need to see an enum from within a namespace. The below code works fine with
class, struct, and union. What gives? As the code says, if I employ the
using directive, I'm ok.


You probably want to restrict your C++ questions to comp.lang.c++. When
you post to both that newsgroup and comp.lang.c, you really should have a
question which could be answered in either language. Those questions are
becoming rarer, with both C++ features not part of C and C features not
part of C++, as well as situations in which the answers are different --
either because the languages are different or because the usual idiom and
normal practice is different in the two languages.

In this case, there is no "using directive" or "using declaration" in C.
Namespace rules differ in the two languages, and named namespaces are not
part of C at all.

I have set followups to comp.lang.c++ only. Should you have a C question,
feel free to post that in comp.lang.c.

[C++ content follows, topical for one of the xposted newsgroups; please
ignore c.l.c]
Why not just use:

namespace Traffic
{
enum Light
{ red, yellow, green };
}

int main(void)
{

Traffic::Light broken = Traffic::red;
return broken;
}

--
Martin Ambuhl

Nov 13 '05 #4

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

11
37123
by: Alexander Grigoriev | last post by:
Not quite new version of GCC that I have to use, craps with the following code: enum E; enum E { e }; That is, it doesn't accept forward declaration of enum. C++ standard text doesn't explicitly say about enum's forward declaration, but one example shows it in 18.2.1, clause 4:
20
4872
by: Glenn Venzke | last post by:
I'm writing a class with a method that will accept 1 of 3 items listed in an enum. Is it possible to pass the item name without the enum name in your calling statement? EXAMPLE: public enum EnumName FirstValue = 1 SecondValue = 2 ThirdValue = 3
4
642
by: Marshall Mills | last post by:
As I understand it, loaded statement, a using declaration should be all I need to see an enum from within a namespace. The below code works fine with class, struct, and union. What gives? As the code says, if I employ the using directive, I'm ok. /* built with Visual C++ 6, SP 5 */ namespace Traffic { enum Light { red, yellow, green }; }
4
3060
by: Chris | last post by:
I've lurked around long enough... Time to interract =) I'm trying to make sense of the following. I can't quite wrap my head around what this is actually doing: ------------- typedef enum { DOUBLE_LIST, INT_LIST } DATA_TYPE; typedef struct { DATA_TYPE type;
10
5846
by: James Brown | last post by:
I have the following enum declared: enum TOKEN { TOK_ID = 1000, TOK_NUMBER, TOK_STRING }; (it goes on and on like that) This is what I would like to do: TOKEN t1 = TOK_ID; // ok TOKEN t2 = 5; // compile error (cannot convert from
4
5740
by: marc.gibian | last post by:
I have been trying to improve the quality of my C# and ADO.NET coding. One of the books I've read strongly advises against using string values to address individual values in DataRow objects. This rings true to me after years of avoiding string lookups whenever possible. But, when I attempted to implement this recommendation I appear to run into casting issues. Thus: enum myFields { field1 = 0, field2 = 1
10
3924
by: Randy | last post by:
Hi, Can anyone point me to a complete, compilable example of Besser's ENUM++ mechanism? I downloaded it from CUJ and gave it a try but got errors just trying to compile the header enum.h. --Randy Yates
1
2469
by: Randy | last post by:
Hi, I downloaded and tried the ENUM++ code from CUJ http://www.cuj.com/documents/s=8470/cujboost0306besser/ but can't even get it to compile (see following). I have also downloaded and installed the boost library. This is using gcc under FC3.
2
2124
by: Randy | last post by:
Hi, I downloaded and tried the ENUM++ code from CUJ http://www.cuj.com/documents/s=8470/cujboost0306besser/ but can't even get it to compile (see following). I have also downloaded and installed the boost library. This is using gcc under FC3.
8
8587
by: benn | last post by:
Here's the setup... Defines.h file contains: enum DAY { monday, tueday }; DayFunctions.h contains prototype: void printIsMonday ( enum DAY currentDay); DayFunctions.c contains:
0
9957
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look ! Part I. Meaning of...
0
9799
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it. First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
0
11173
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed. This is as boiled down as I can make it. Here is my compilation command: g++-12 -std=c++20 -Wnarrowing bit_field.cpp Here is the code in...
0
10772
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth. The Art of Business Website Design Your website is...
0
10434
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
1
7988
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules. He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms. Adolph will...
0
7143
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert into image. Globals.ThisAddIn.Application.ActiveDocument.Select();...
0
5810
by: TSSRALBI | last post by:
Hello I'm a network technician in training and I need your help. I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs. The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols. I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
0
6011
by: adsilva | last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.