Variant Comparison

Understanding C++ variant semantics and type matching

This is a hard C++ language-knowledge question that tests deep familiarity with std::variant semantics, type deduction, and the rules governing variant assignment and comparison. It rewards precision over intuition—the kind of question that separates candidates who have read the standard from those who rely on surface-level knowledge.

Working through problems like this requires understanding how variants resolve overloads during assignment, which type the variant actually holds after an operation, and how equality operators behave when types may or may not match. Strong candidates trace through the exact sequence of constructor calls and type conversions, rather than guessing at output.

• Variant type state and the active alternative
• Implicit conversions and overload resolution in variant assignment
• Operator overloading and type compatibility in comparisons