Re: [boost] ABI issues with -std

On 08/20/18 10:37, Olaf van der Spek wrote:

On Sun, Aug 19, 2018 at 10:57 PM, Andrey Semashev via Boost wrote:

...

I solved this in Boost.Log this way:

struct Y { void f( X const& x );

#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)

void f( X&& x ) { f_move(x); }

#endif

private: void f_move(X& x); };

Only works if void f( X&& x ) is inlined and even then it still violates ODR doesn't it?

If `f( X&& x )` is not inlined then it means it is ODR-used in the user's code and left there as a standalone function. I don't see the problem. ODR is violated but not in the harmful way. ABI is the same, API is 99.9% compatible (leaving 0.1% for weird cases where you try to exchange a pointer to Y::f between code bases for C++03 and C++11).

...

As a slightly different variant of the Boost.System2 solution, I can suggest building multiple Boost.System binaries, one per ABI we can support.

That'd require library name mangling on Linux and adding the std level to the name..

Not necessarilly. The base name of Boost.System with the new ABI could be different.