The relationship between Boost and the C++ standard library might provide a good example (especially in recent years, as there's been sustained focus on expandi

The relationship between Boost and the C++ standard library might provide a good example (especially in recent years, as there's been sustained focus on expanding stdlib). Boost has a stringent peer review and comment period. Sometimes I think they let in designs that are too clever, but they rarely let in the clunkers that are seen in Python's standard library. People then gain experience with it and sometimes subtle issues emerge. Those issues can be fixed, either in Boost itself or when libraries move from Boost to stdlib (and sometimes the issues inform language features). While C++'s standard library is not "batteries included" like Python's, it's been very gratifying to see it expand slowly and surely over the last few years.