Const Caller

What this C++ const-correctness question tests

This is a hard C++ language-knowledge question that probes deep understanding of const semantics, reference binding, and the dangers of const_cast. It rewards candidates who can trace through the layers of const qualification and reason about undefined behaviour, not just syntax.

The question requires you to distinguish between const objects, const pointers, const references, and the contract violations that arise when you strip away const qualifiers. It tests whether you understand which casts are safe in principle and which invoke undefined behaviour in practice—a critical skill for systems programming and code review in competitive trading environments.

• Const qualification and the one-definition rule
• Reference semantics and lifetime
• const_cast and when it is safe vs. undefined
• Compiler optimisation and const objects