LLVM? Yes. Clang? No. The front-end compiler and standard library are written from scratch, but it uses LLVM as the backend. The standard library is not yet co

LLVM? Yes. Clang? No. The front-end compiler and standard library are written from scratch, but it uses LLVM as the backend. The standard library is not yet complete, but it's amazing how it uses Circle's unique features to implement in a very elegant and efficient manner certain classes like variant and tuple which are absolute monstrosities of complexity in clang/g++/MSVC.