title: g++ always backward-compatible with "older" static libraries?
body: <p>I have a few static libraries, which I'm not the owner of, compiled with an old version of g++ 4.3.2 (c++11/c++0x not activated).</p>
  
  <p>When I compile my code with g++ 4.6 (no c++11) and link it using g++ 4.6 with these 
  static libraries, it links fine and I do not seem to get any issues at runtime (not tested everything though).
  I'm tempted to think that forward compatibility is OK.</p>
  
  <p>Now I'd like to compile my code with gcc 4.8 with c++11 and still link it with those same, not recompiled static libraries.</p>
  
  <p><strong>Are ABI changes in g++ only an issue for linkage forward compatibility or can one get backward compatibility issues too?</strong></p>