Edward Diener wrote:
Haven't we already basically agreed, going forward with Boost, that a library can use C++11 features and the C++11 Standard Library without informing end-users in advance that it is going to do so, if previously it supported C++03 ?
In theory. But theory and practice differ in practice. The theory of libraries as independent islands does not describe reality; we're a community, a team, and we tend not to do things that will create problems for other maintainers, such as unilaterally dropping C++03 support forcing all dependent libraries who still wish to support C++03 to deal with it somehow as if their maintainers had nothing better to do all day. Dropping C++03 is a collective decision that Boost will take and announce as a single entity, and then everyone can move on to C++11 with clear conscience.