What's the alignment?

Understanding type alignment queries in C++

This is a straightforward question on C++ language fundamentals, testing whether you know the standard mechanism for inspecting type properties at compile time. It appears frequently in interviews at firms that work with performance-critical systems where memory layout matters—particularly in high-frequency trading, where engineers optimize data structures for cache efficiency and minimal padding.

The question probes practical knowledge of how to programmatically determine how a type is aligned in memory. This is essential when designing structures for low-latency communication, shared memory, or hardware-aligned buffers. A solid answer demonstrates familiarity with the standard library tools available in modern C++ for introspection.

• Compile-time type introspection
• Memory layout and cache-line boundaries
• Padding and structure packing