Re: [boost] [Filesystem] problems with g++ -std=c++0x

Subject: Re: [boost] [Filesystem] problems with g++ -std=c++0x
From: Roland Bock (rbock_at_[hidden])
Date: 2010-08-26 15:37:31

On 08/26/2010 08:44 PM, Bryce Lelbach aka wash wrote:
>>>> In the meantime, I found that variadic templates work just fine in
>>>> gcc-4.4,
>>>> even without the -std=c++0x option, but they emit warnings. According
>>>> to the
>>>> gcc mailing list, these cannot be suppressed (except by turning on said
>>>> option).
>>>>          
> I took a look at the gcc source - there's definitely no flag to disable
> that warning, but #pragma GCC system_header will do the trick (recent
> versions of libstdc++ use variadic templates with or without c++0x
> support enabled). It won't work in C++ source files, just in headers;
> adding #pragma GCC system_header will tell GCC to treat everything from
> the pragma to the end of the file as a system header. Note that this
> will disable a boatload of other warnings.
>
>    

Bryce,

yeah, the system_header pragma or the -isystem option are pretty cool if 
you know for sure that all warnings can be safely ignored. But when 
developing something new, this is rarely the case.

So what I am doing now (seems to work fine):

Most of the time, I compile without -std=c++0x, because most of the 
time, I don't use those new features. But there are some rather isolated 
classes that use variadic templates for a type-safe communication layer 
for postgresql. Those classes are compiled with -std=c++0x.

Thanks and regards,

Roland