Short String, Big Optimization

Implementing small-buffer string optimization in C++

This medium-difficulty coding problem tests whether you understand how real-world standard library containers balance performance across common and uncommon cases. You will build a simplified ShortString class that stores short strings inline — avoiding heap allocation and cache misses — while gracefully upgrading to dynamic allocation for longer strings.

The problem requires you to reason carefully about memory ownership, lifetime, and the differences between copy and move semantics. Every operation (construction, assignment, destruction) must decide whether to use the inline buffer or the heap, and moves must transfer ownership without unnecessary copies. Interviewers care about whether your implementation is correct under all four assignment paths, handles edge cases like empty strings, and keeps the invariants sound.

• Memory layout: discriminating local vs. heap storage within a single object
• Copy vs. move semantics and noexcept guarantees
• Pointer aliasing and ownership transfer in move operations
• Null termination and buffer bounds checking