Declarative Control Flow with C++ Scope Guards

Pointed to in threads on defer, scope_exit and RAII as the clearest treatment of scope guards.

Andrei Alexandrescu's CppCon 2015 talk on handling exceptional control flow declaratively in C++. It uses scope guards with success and failure variants, built on std::uncaught_exceptions, to replace ad hoc RAII classes and rethrowing try/catch blocks.