What I learned about language and library design by working on Swift

When Dave began going to C++ committee meetings in the late 1990's, he had no idea the impact it would have on his thinking. That work, and his participation in Boost, shaped a clear worldview about how things should be done and what was possible, launching a phase of huge personal and professional growth for him. By 2013, though, that phase had run its course, so Dave closed down his C++-focused consulting company and joined a team at Apple in developing a next-generation programming language. Although everyone on the team was an expert C++ programmer, they brought a diverse set of influences to the table, and the eventual results surprised all of them. For Dave, the insights he gained about what a language could be, and how to build libraries, were even more surprising than the shape of Swift itself. This talk is the story of that journey.