Expected Behavior in Mixing -std=c++0x and default std?

Expected Behavior in Mixing -std=c++0x and default std?

[Hei Chan]

Hi,

If I have a static library A that builds with default std with another header only library B, and then my program links library A and uses some classes in library B with -std=c++0x.  Will this usage create any issue?

I am running into an issue that one of the member variables in library B (boost ASIO to be precise) has a different memory address (only off by 4 bytes) over time.

Any input is welcome.

Thanks in advance.


Cheers,
Hei
P.S. I am using GCC 4.6.x on CentOS 6.5.

Re: Expected Behavior in Mixing -std=c++0x and default std?

[Jonathan Wakely]

On 8 April 2014 09:06, Hei Chan wrote:
> Hi,
>
> If I have a static library A that builds with default std with another header only library B, and then my program links library A and uses some classes in library B with -std=c++0x.  Will this usage create any issue?
>
> I am running into an issue that one of the member variables in library B (boost ASIO to be precise) has a different memory address (only off by 4 bytes) over time.
>
> Any input is welcome.
>
> Thanks in advance.
>
>
> Cheers,
> Hei
> P.S. I am using GCC 4.6.x on CentOS 6.5.

With GCC 4.6.x, 4.7.2 or 4.8.x that should work OK.  With GCC 4.7.0 or
4.7.1 there would be a problem if B uses std::list.

You should be able to find why the offset of the ASIO type changed, it
might not be due to a std::lib type.

Re: Expected Behavior in Mixing -std=c++0x and default std?

[Hei Chan]

Hi,

I am using 4.6.2.

When I ran my application (with mixed std flags) with Valgrind, Valgrind claimed that the member variable was uninitialized because at that moment, the address of that variable was off by 4 bytes.

The type of that variable is boost::asio::detail::atomic_count.

But I think that the type probably is irrelevant to this problem?



On Tuesday, April 8, 2014 7:31 AM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
On 8 April 2014 09:06, Hei Chan wrote:

> Hi,
>
> If I have a static library A that builds with default std with another header only library B, and then my program links library A and uses some classes in library B with -std=c++0x.  Will this usage create any issue?
>
> I am running into an issue that one of the member variables in library B (boost ASIO to be precise) has a different memory address (only off by 4 bytes) over time.
>
> Any input is welcome.
>
> Thanks in advance.
>
>
> Cheers,
> Hei
> P.S. I am using GCC 4.6.x on CentOS 6.5.

With GCC 4.6.x, 4.7.2 or 4.8.x that should work OK.  With GCC 4.7.0 or
4.7.1 there would be a problem if B uses std::list.

You should be able to find why the offset of the ASIO type changed, it
might not be due to a std::lib type.