Erase it.

Understanding type-erasure in C++17

This is an easy question on C++17 language features, testing whether you recognize which standard library tools rely on type-erasure—a technique that hides concrete type information behind a uniform interface. Quant firms ask questions like this to gauge foundational knowledge of modern C++ idioms, since type-erasure appears frequently in high-performance libraries and frameworks.

Type-erasure allows you to work with heterogeneous types through a common abstraction, trading some compile-time type safety for runtime flexibility. In C++17, several standard additions introduced or relied on this pattern. To answer correctly, you need to distinguish between features that preserve type information at compile time and those that deliberately erase it at the boundary between caller and implementation.

• Runtime polymorphism vs. compile-time generics
• Virtual function tables and dynamic dispatch
• Template specialization and instantiation