Chained Pipeline

What this C++ code-tracing question tests

This is a hard C++ language-knowledge question that asks you to reason through the execution and output of a non-trivial code snippet. It rewards careful attention to operator precedence, method chaining, and the subtle semantics of temporary objects and return values.

Questions like this appear in technical interviews to verify that candidates can read and predict the behaviour of real C++ code without running it—a critical skill when code review, debugging, and understanding library internals are part of the job. The challenge lies in tracking state changes across chained calls and understanding exactly when and how values are evaluated.

• Method chaining and fluent interfaces
• Return-by-value and temporary object lifetimes
• Operator evaluation order and associativity
• Side effects and mutation across call sequences