📖 Book · cpp17 · medium
🆕 std::variant: type-safe state machines
A closed sum type + std::visit = exhaustive, heap-free, no-vtable dispatch.
std::variant as a type-safe union and the std::visit + overloaded-lambda idiom for exhaustive dispatch, built into a runnable state machine. When to choose a closed variant over an open inheritance hierarchy, plus the access/valueless gotchas.
3 chapters▶ runnable code✦ in-depth animation
▶ See it animated:std::variant & std::visit →
What this book covers
- 01A sum type for C++
- 02std::visit + the overloaded idiom — run it
- 03Access, exceptions & valueless
Read it in full — runnable C++ + step-through animations
Every chapter of std::variant: type-safe state machines ships complete, editable code you compile and run in the browser, plus the same in-depth animations as the lessons.