std::locale does not work here

[Patrick Gräbel]

I know, that there are different supported locale strings on Windows 
(e.g. "eng"), Linux/POSIX (e.g. "en_US") and so on.

Is there a way to test the locale string support? Stroustrup says in his 
  C++ book, that there is a "runtime_error" exception thrown by the 
std::locale's constructor, if the locale string argument is not 
supported by the executing OS. But Cygwin & Debian/stable's gnu stdc++ 
libs do not react on unsupported locale strings...

Is there any gnu stdc++ lib port out there, that supports more than "C"?

-Patrick



Nathan Myers wrote:

> On Tue, Jun 22, 2004 at 02:33:09AM +0200, Patrick Gr?bel wrote:
> 
>>I am using Cygwin (g++-3.3.1) and Debian/stable (g++-3.0.1). The 
>>following call will not throw an "runtime_error" that is described in 
>>Stroustrup's C++ bible:
>>
>>std::locale loc("$$???XXXYYY????!!!");
>>
>>The constructor even accepts locale strings, that do not make sense. 
>>Also the following code will _not_ produce a ',' instead of a '.':
>>
>>std::locale loc("de_DE");
>>double d = 1.76;
>>std::cout.imbue(loc);
>>std::cout << d << std::endl;
>>
>>That's weird. Is g++'s stdc++ lib incompatible to the standard?
> 
> 
> The standard says very little about what makes a useful locale name.  
> If the implementation claims POSIX compatibility, you might reasonably 
> expect POSIX locale names to mean something.  It's all up to the 
> documentation for your implementation, which is likely to defer to the 
> OS.  All you're guaranteed is that "C" or "POSIX" will do something 
> not too unreasonable -- in the opinion of the implementer.  It's 
> called "quality of implementation", and lousy implementations are 
> allowed, and hoped to be out-competed by good ones.  Often, there's
> not much an implementation can do if the OS doesn't help.
> 
> The implication is just that locale name strings should never be 
> compiled in to a portable program.  Get it from a config file,
> environment variable, or "resource".
> 
> (Is this an FAQ?)
> 
> Nathan Myers
> ncm-nospam@cantrip.org
>