Signed Nothing

What this C++ type-system interview question tests

This is a medium-difficulty question that probes your understanding of C++ signed and unsigned integer semantics, type conversions, and how the language handles mixed-type comparisons and arithmetic. It rewards close reading of the C++ standard over guessing.

To solve it, you need to trace through a code snippet and predict its output by reasoning about how the compiler resolves type promotion rules, implicit conversions, and operator overloads. Interviewers use questions like this to verify that you can reason precisely about language behavior rather than rely on intuition—a critical skill in performance-critical systems where undefined behavior or silent type coercion can hide bugs.

• Signed and unsigned integer promotion rules
• Type conversion in mixed expressions
• Comparison and arithmetic operator resolution