What is perfect forwarding with std::forward?
PICTURE THIS: HOW TO EXPLAIN IT
Simple meaning
In templates it preserves value category when passing arguments onward.
WHY — Modern instead of guessing?
Why interviewers care about Modern:
who only read docs from people who shipped.
and tied to C++ work.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1In templates it preserves
value category when passing arguments onward.
- 2Used in emplace and
wrapper factories.
- 3Misusing forward on non-forwarding
refs is a bug.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
In templates it preserves value category when passing arguments onward. Used in emplace and wrapper factories.