https://lyubo.kozlio.com/posts/smallcontainers/ Requires C++17. No dependencies on external libs.
Initial version of SmallVector and SmallString ripped out from LLVM. Original LLVM license notice:
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.