What does std::move actually do?
A staple at every firm on this list, and the phrasing of the question is a trap: the name says move, the function does not move. What it does is change how overload resolution sees the argument.
Exam
Answer these to pass this module.
Start here rather than at the reading. Whatever you miss tells you which part of Learn you actually need — and anything you get right is a part you can skip.
What does std::move compile down to?
After `auto b = std::move(a);` where a is a std::string, what may you do with a?
`const std::string s = "hi"; auto t = std::move(s);` — what actually happens?
Explain mode
What does std::move actually do?
Answer without using the word 'move' as a verb. If you can explain it without that word, you understand it.
Your own words, two or three sentences, nothing looked up. The rubric unlocks once you submit.
Graded against a set rubric. Three a day on a free account. Need more? Ask on our Facebook page — it's free.
Learn
Value categories (lvalue, xvalue, prvalue), rvalue references, what std::move compiles down to, and where the actual moving happens.
Ask an AI to teach you this
I'm preparing for a quant developer interview on "What does std::move actually do?" Concepts I need to own: value categories (lvalue, xvalue, prvalue), rvalue references, what std::move compiles down to, and where the actual moving happens. Run this as interview practice, not a lecture. One concept at a time. Wait for my answer before moving on. Per concept: 1. Teach it. Lead with the one-line core claim, then a few short paragraphs. Assume I write C++ but have never had this explained properly. No jargon without defining it. 2. "The 60-second version" — what a strong candidate would SAY out loud. First person, spoken register, no bullets, no headers. That's what I'm rehearsing. 3. Ask me one question that exposes whether I only think I understood it. When I answer, reply in exactly this shape: Verdict: correct / partly correct / wrong — one line on what's wrong. What you missed: only if something's missing. 2-3 sentences. Vocabulary: only if I used a wrong or vague term. Give the right one. Example answer: the model spoken answer, 30 seconds max, first person. More info: define any term I probably don't know, one line each. Follow-up probe: the one question an interviewer asks someone who gave that model answer. Skip any section that doesn't apply. Don't pad. If I'm wrong, say wrong — don't soften it. Do not write my implementation for me. If I ask, refuse and ask what I'd try instead — I need to defend this code with the editor closed.
Do
Ship
Practice with AI
Use these to make the AI your examiner, not your author. If the AI wrote the code, this node doesn't count — you can't defend a design you didn't make.
- P8 — grade my explanation against the rubric, and name what I left out
- P6 — defend your design decisions with the code closed