Finally, a decent C++ developer called in.

About this video

• Video Title: Finally, a decent C++ developer called in.
• Channel: Coding Jesus
• Speakers: Coding Jesus (Interviewer), Candidate (Interviewee)
• Duration: 00:17:19

Overview

This video is an interview with a C++ developer candidate. The interviewer tests the candidate's knowledge on various C++ concepts, including smart pointers, concurrency, memory ordering, struct padding, templates, move semantics, data structures (vectors and deques), and C++ features like if constexpr. The candidate demonstrates a good understanding of many topics, with some areas for further development.

Key takeaways

• Smart Pointers: Discussed weak_ptr validity checking with lock() and the thread-safety of shared_ptr (specifically its reference counting mechanism).
• Concurrency & Memory Ordering: Touched upon atomics and the distinction between wait-free and lock-free programming.
• Struct Padding: Explained that compilers add padding to structs for alignment to improve performance, as unaligned access can lead to multiple memory accesses instead of one.
• Template Metaprogramming: Explored scenarios like preventing template instantiation for specific types using enable_if or = delete and using std::ref to modify arguments passed by copy.
• Move Semantics: Discussed the behavior of moving a const object, which results in a copy, not a move, and a compile-time error if the type doesn't support it.
• Vector and Deque Implementation: Covered iterator invalidation in vectors during reallocation, the purpose of reserve and shrink_to_fit, and the underlying implementation of a deque using an array of pointers to contiguous memory chunks.
• make_shared vs. shared_ptr(new T): Highlighted the efficiency and exception safety benefits of make_shared due to single memory allocation for the control block and the object.
• C++ Features: Briefly mentioned if constexpr and its behavior in conditional compilation.