Cannot Overload

Understanding operator overloading limitations in C++

This is a medium-difficulty C++ language-knowledge question that tests whether you understand the full scope of what can and cannot be customized through operator overloading. It is a common screening question at firms that rely on C++ for systems and quant infrastructure, where deep language familiarity distinguishes strong candidates.

C++ allows you to redefine the behaviour of most operators—arithmetic, comparison, assignment, subscript, function call, and stream insertion/extraction among them. However, a small set of operators are deliberately excluded from overloading, either because they have intrinsic language semantics that would become meaningless if changed, or because their meaning is tied to fundamental type operations. Recognizing which ones sit outside the overloadable set is part of solid C++ foundation knowledge.

• The scope-resolution operator and member-access operators
• Operators that depend on compile-time semantics and control flow
• Operators bound to built-in type identity and memory layout