[boost] C++11 variant of the gcc toolset?

Currently, when I want to test under g++ in C++11 mode, I use b2 toolset=gcc cxxflags=-std=c++11 This works, but (a) prevents me from combining this with other toolsets, (b) prevents me from testing both 03 and 11 at once, and (c) boost.build doesn't treat the two modes of the gcc toolset as distinct and uses the same directory for both. Am I missing something simple, or if not, shouldn't we have a separate gcc11 toolset that is exactly the same as the gcc toolset, but with -std=c++11 applied?