Tuple-Fed Addition

Understanding variadic templates and tuple unpacking in C++

This is a medium-difficulty C++ language-knowledge question that tests your grasp of variadic templates, tuple operations, and template metaprogramming. It's the kind of question used to assess whether a candidate can read and predict the behaviour of modern C++ code that relies on compile-time abstractions.

To answer it correctly, you need to trace through how tuples are constructed, how variadic parameter packs are expanded, and how template functions resolve when given composite types as arguments. The question rewards understanding the interaction between language features rather than memorization—specifically, how the compiler instantiates templates and what values flow through the call stack.

• Variadic template parameter packs and expansion
• Tuple construction and element access
• Template instantiation and type deduction
• Function overload resolution with pack expansion