Assume that I have
 using namespace abc;
 using namespace def;
somewhere in the beginning.  A few functions in abc
and def have the same function prototype.  It would
be fine if I don't use these functions, or in the
specific places, I have
 using abc::operator<<;
 using abc::operator>>;
 using abc::getline
the above 3 statements would solve the name clashing
problem for the above 3 functions.  However, what if
there are more clashes, won't it be nice to have
something like:
 using namespace abc
  {
    cin >> a;
    cout << a;
    getline (cin, linebuf);
  };
?  Possible?
Please don't tell me to use
 {
   using namespace abc;
 }
It's not going to work.  There are significant
differences between these two.

Heng Yuan
heng@ag.arizona.edu
hyuan@ucdavis.edu

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In article <8patll$nsh$1@mark.ucdavis.edu>,
  hyuan@runner.ucdavis.edu (Heng Yuan) wrote:
> Assume that I have
>  using namespace abc;
>  using namespace def;
> somewhere in the beginning.  A few functions in abc
> and def have the same function prototype.  It would
> be fine if I don't use these functions, or in the
> specific places, I have
>  using abc::operator<<;
>  using abc::operator>>;
>  using abc::getline
> the above 3 statements would solve the name clashing
> problem for the above 3 functions.  However, what if
> there are more clashes, won't it be nice to have
> something like:
>  using namespace abc
>   {
>     cin >> a;
>     cout << a;
>     getline (cin, linebuf);
>   };
> ?  Possible?
> Please don't tell me to use
>  {
>    using namespace abc;
>  }
> It's not going to work.  There are significant
> differences between these two.
I don't understand you - the second form you have shown will do
*exactly* what you have just asked.  For example:

#include <iostream>

void f()
{
   using namespace std;
   cout << "Hello, C++ world!\n" << endl;
}

int main()
{
   cout << "Hello, C++ world!\n" << endl;
   f();
}

f() should compile without error, but main() should give you errors that
'cout' and 'endl' are undeclared identifiers.  Isn't that what you want?

--
Jim
This message was posted using plain text only.  Any hyperlinks you may
see were added other parties without my permission.
I do not endorse any products or services that may be hyperlinked to
this message.


Sent via Deja.com http://www.deja.com/
Before you buy.

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In article <8phgu4$cu6$1@mark.ucdavis.edu>,
Heng Yuan <hyuan@runner.ucdavis.edu> wrote:
>....  Imagine that there are a number of
>namespaces which are enabled ... there are a few functions
>in these namespaces share the same prototype.....
>So I propose something like:
> using namespace abc
>   {
>     cout << obj;
>   }
>This form forces functions insides the brackets in abc take
>precedence over global and other namespace functions.  It is
>very different from
> using namespace abc;
>which just tells the compiler to load the function prototypes
>of abc as part of default function lookup table.

I know where you are coming from, and other languages have
something similar in some cases, but assuming that I'm
understanding what it is that you want to do I just don't really
see the magic bullet given the constraints you've laid out here,
that is, not over say just writing a function to do the same thing.

- Greg
--
Comeau Computing / Comeau C/C++ ("so close" 4.2.44 betas starting)
TRY Comeau C++ ONLINE at http://www.comeaucomputing.com/tryitout
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You got me wrong totally.  Imagine that there are a number of
namespaces which are enabled by
 using namespace abc;
 using namespace def;
 using namespace ghi;
However, there are a few functions in these namespaces share
the same prototype.  Thus, in order to use the specific functions,
I would have to do either:
 using abc::operator<<;
 cout << obj;
or
 abc::operator<< (cout, obj);
.  However, if I have a block of codes which involves more than
one functions, it would be extremely tedious to write them these
ways.  Also, if I want to switch the namespace functions, it
would be a pain to change all of them.  So I propose something
like:
 using namespace abc
   {
     cout << obj;
   }
This form forces functions insides the brackets in abc take
precedence over global and other namespace functions.  It is
very different from
 using namespace abc;
which just tells the compiler to load the function prototypes
of abc as part of default function lookup table.

In article <8pbmg6$obk$1@nnrp1.deja.com>,
Jim Hyslop  <jim.hyslop@leitch.com> wrote:
>In article <8patll$nsh$1@mark.ucdavis.edu>,
>  hyuan@runner.ucdavis.edu (Heng Yuan) wrote:
>> Assume that I have
>>  using namespace abc;
>>  using namespace def;
>> somewhere in the beginning.  A few functions in abc
>> and def have the same function prototype.  It would
>> be fine if I don't use these functions, or in the
>> specific places, I have
>>  using abc::operator<<;
>>  using abc::operator>>;
>>  using abc::getline
>> the above 3 statements would solve the name clashing
>> problem for the above 3 functions.  However, what if
>> there are more clashes, won't it be nice to have
>> something like:
>>  using namespace abc
>>   {
>>     cin >> a;
>>     cout << a;
>>     getline (cin, linebuf);
>>   };
>> ?  Possible?
>> Please don't tell me to use
>>  {
>>    using namespace abc;
>>  }
>> It's not going to work.  There are significant
>> differences between these two.
>I don't understand you - the second form you have shown will do
>*exactly* what you have just asked.  For example:
>
>#include <iostream>
>
>void f()
>{
>   using namespace std;
>   cout << "Hello, C++ world!\n" << endl;
>}
>
>int main()
>{
>   cout << "Hello, C++ world!\n" << endl;
>   f();
>}
>
>f() should compile without error, but main() should give you errors that
>'cout' and 'endl' are undeclared identifiers.  Isn't that what you want?
>
>--
>Jim
>This message was posted using plain text only.  Any hyperlinks you may
>see were added other parties without my permission.
>I do not endorse any products or services that may be hyperlinked to
>this message.
>
>
>Sent via Deja.com http://www.deja.com/
>Before you buy.
>
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>


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