Re: [boost] [Config] Support for switching between std:: andboost:: equivalents.

John Maddock wrote:

Right. But if lib X prefers/needs to use the Boost version always, they don't have to use this mechanism.

What I'm saying is more like lib X has a dual interface, but _the user_ of lib X wants to use the boost:: version, whereas lib X detects C++11 and provides the std:: version. Lib X is #if CXX11 void libx_f( std::regex const & rx ); #else void libx_f( boost::regex const & rx ); #endif but the user wants to continue using boost::regex under C++11. This could in principle be addressed in some way by giving the user the option to override libX's decision to go with std::regex.