decltype almost always yields the type of a variable or expression without any modifications. For lvalue expressions of type T other than names, decltype always reports a type of T&.

auto type deduction is usually the same as template type deduction, with an exception in the case of braced initializer. Also, in C++14, as a function return type or a lambda parameter, auto implies template type deduction instead of auto type deduction.

There are three sets of rules for type deduction in modern C++: one for function templates, one for auto, and one for decltype. Without a solid understanding of how deduction operates, effective programming in modern C++ is all but impossible.

As a highly available and scalable distributed data store, the design principles of Dynamo features high availability for writes (via reconciliation during reads), incremental scalability (consistent hashing), symmetry, decentralization, and heterogeneity (via virtual nodes).

There are five points worth noting if we want to mix C++ and C in the same program.