I hate extern.

What this C++ language-knowledge question tests

This is a medium-difficulty question that probes your understanding of extern "C" linkage in C++—a feature that frequently trips up engineers in code review and integration scenarios. It appears in technical interviews because the distinction between C and C++ linkage is subtle but consequential for real systems, especially when bridging legacy code or interfacing with C libraries.

To answer correctly, you need to understand why and when C++ code declares external C linkage, what happens to function names and calling conventions under each linkage model, and how the linker resolves symbols differently. The question rewards precise knowledge of language semantics over guesswork.

• Name mangling and symbol resolution in C++ vs. C
• Linkage specifications and their scope
• Common patterns: wrapping C headers, exposing C++ APIs to C callers
• Implications for binary compatibility and ABI