boost::icl::swap causes ambiguity with std::swap with ADL

[Nathan Thomas <nthomas@…>]

With C++11, the swap() function overload in boost::icl is ambiguous with std::swap due to ADL. I'm using boost 1.53, but this doesn't appear to be addressed in git yet either. It think it's the exact same problem previously addressed in Boost.Variant (​https://svn.boost.org/trac/boost/ticket/2839).

I've applied the same fix (i.e., using separate template params for two arguments to swap, making it less specialized than std::swap) to my local copy of boost, and it appears to resolve it.

I'm using clang 3.4 / libstdc++ from gcc 4.7.2 / boost 1.53, compile line ==> clang -std=c++11 -o test_adl test_adl.cc

test file and error message attached.

Thanks, --Nathan