Compile Time Collapsing

What this compile-time template metaprogramming problem tests

This is a hard C++ problem that assesses your ability to reason about and manipulate types at compile time using template specialization and recursion. Rather than running code at runtime, you are implementing logic that the compiler executes during type checking, producing a new type as output.

The problem requires you to understand how to define recursive template specializations, inspect template parameters, and conditionally generate new types based on comparisons between those parameters. You'll need to build a solution that processes a sequence of numbers, filters out duplicates, and reconstructs a valid result type—all without a single runtime instruction.

• Template specialization and partial specialization
• Variadic template parameters and recursion
• Type accumulation and conditional type generation
• Base cases and termination in compile-time recursion

This style of problem is common at quantitative trading firms that value deep C++ expertise, particularly in high-frequency trading environments where template metaprogramming can eliminate runtime overhead. Success here demonstrates that you can think in types, not just values.