Core · Module 7 · Lesson 2 of 11

string: Characters, Storage and Small-String Optimization

Store text without manual new and delete, compare size, capacity and null terminators, and predict when small-string optimization avoids the heap.

ProAbout 10 minutes

By the end you can

Explain size, capacity and null terminator guarantees for std::string
Predict when short strings avoid heap allocation through SSO
Use reserve, c_str, at and operator+= without invalidating views

Builds on vector: The Default Container and How It Grows.

01 · A question first

Your catalogue titles average nine characters, yet every title triggers a heap allocation and your profiler glows. Why does one string allocate while another never touches the heap, where does the terminating null live, and when does a pointer into a string expire?

Make a guess before you read on.

02 · The idea

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What's inside

Start with the problem
How the idea works
Why it is correct
What it costs
Pitfalls and variations
How to keep views alive across growth
Where it is used