std::variant：类型安全联合体 | C++

本章覆盖：`std::variant`；alternatives；active alternative；`std::get`；`std::get_if`；`std::visit`；tagged union；compile-time closed set；error state / AST / message 类型；variant vs inheritance；union 的更安全替代场景。

本章知识点

  • std::variant
  • alternatives
  • active alternative
  • std::get
  • std::get_if
  • std::visit
  • tagged union
  • compile-time closed set
  • error state / AST / message 类型
  • variant vs inheritance
  • union 的更安全替代场景