Is std::wcout really required?

[Amit Kumar]

Output of all the four statements are the same on Visual studio:

std::cout << "Hello\n";
std::wcout << "Hello\n";
std::cout << L"Hello\n";
std::wcout << L"Hello\n";

If cout and wcout can handle both char strings and wide char strings
then why do we need wcout?

 

[Developer]

They are not exactly the same

 

[Thomas Matthews]

Output of all the four statements are the same on Visual studio:

std::cout << "Hello\n";
std::wcout << "Hello\n";
std::cout << L"Hello\n";
std::wcout << L"Hello\n";

If cout and wcout can handle both char strings and wide char strings
then why do we need wcout?

Yes, wcout is required since changing the functionality of cout
would screw up a bunch of legacy programs.

However, there is nothing stopping _you_ from overloading
cout to perform the way _you_ think it should.

--
Thomas Matthews

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Other sites:
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http://www.sgi.com/tech/stl -- Standard Template Library

 

[Bo Persson]

Output of all the four statements are the same on Visual studio:

std::cout << "Hello\n";
std::wcout << "Hello\n";
std::cout << L"Hello\n";
std::wcout << L"Hello\n";

If cout and wcout can handle both char strings and wide char strings
then why do we need wcout?

No, the results are not the same. Outputting a wide string to cout
differs from the others.

On recent versions of Windows, the question is "Why do we need cout,
when wcout works for both narrow and wide strings?".

On other systems, the question might be different.


Bo Persson

 

[Donkey Hottie]

On recent versions of Windows, the question is "Why do we
need cout, when wcout works for both narrow and wide
strings?".
On other systems, the question might be different.

So why the Windows implementation defines a new wcout, and not re-define
cout in the first place?

 

[Bo Persson]

So why the Windows implementation defines a new wcout, and not
re-define cout in the first place?

It is not new, they are both in the language standard. It is just that
as newer Windows versions internally uses wchar_t for characters,
wcout is a better match.


Bo Persson

 

[Alf P. Steinbach]

* Bo Persson:

It is not new, they are both in the language standard. It is just that
as newer Windows versions internally uses wchar_t for characters,
wcout is a better match.

I'm not sure I understand what you're talking about.

Could you sort of elaborate?

 

[Bo Persson]

* Bo Persson:

I'm not sure I understand what you're talking about.

Could you sort of elaborate?

I'm not sure I understand what you don't understand.

Is it the design to use a 16-bit character set in the OS, but keep
char and cout 8-bit wide? Or is it my preference of using wcout for
the occational console output, taking advantage of a 1-to-1 mappning
to the resulting byte stream?


Bo Persson

 

[Alf P. Steinbach]

* Bo Persson:

I'm not sure I understand what you don't understand.

Is it the design to use a 16-bit character set in the OS, but keep
char and cout 8-bit wide?

No, I understand that well.

It was done in a stupid way that made console windows effectively incompatible
with the rest of Windows, for the ordinary end user.

Or is it my preference of using wcout for
the occational console output, taking advantage of a 1-to-1 mappning
to the resulting byte stream?

There is no 1-to-1 mapping.

It is mapping that *loses* information.

Even if you use some non-standard UTF-8 "locale" you're screwed, because in
Windows XP the UTF-8 codepage, 65001, does not work. "Does not work" means, for
example, that ordinary commands stop having any effect when you switch to this
codepage (and e.g. the 'more' command will, silly enough, report that it's out
of memory). So it "can't" be used for output until Windows XP is well dead.


Cheers & hth.,

- Alf