variant

问题 How can I parse nested json in c++? I am looking for a json parser that is capable of parsing nested json. Especially this field in the example json below: optional<variant<bool, Secondary>> secondary; It is type composition of optional and variant . Though only the full example can surface the problem in a clearer way, a minimal starting point example would be this one: [ {}, { "secondary": false }, { "secondary": { "chance": 10, "boosts": { "spd": -1 } } }, { "secondary": { "chance": 30,

问题 How can I parse nested json in c++? I am looking for a json parser that is capable of parsing nested json. Especially this field in the example json below: optional<variant<bool, Secondary>> secondary; It is type composition of optional and variant . Though only the full example can surface the problem in a clearer way, a minimal starting point example would be this one: [ {}, { "secondary": false }, { "secondary": { "chance": 10, "boosts": { "spd": -1 } } }, { "secondary": { "chance": 30,

问题 When one already knows all the finite number of types involved in some code which needs dynamic polymorphism, using enum can be better for performances compared to using Box since the latter uses dynamic memory allocation and you'll need to use trait objects which have virtual function call as well. That said, compared to the equivalent code in C++ using std::variant and std::visit , looks like Rust in this scenario has more boilerplate coding involved, at least for me (I have not yet learned

问题 When one already knows all the finite number of types involved in some code which needs dynamic polymorphism, using enum can be better for performances compared to using Box since the latter uses dynamic memory allocation and you'll need to use trait objects which have virtual function call as well. That said, compared to the equivalent code in C++ using std::variant and std::visit , looks like Rust in this scenario has more boilerplate coding involved, at least for me (I have not yet learned

问题 When one already knows all the finite number of types involved in some code which needs dynamic polymorphism, using enum can be better for performances compared to using Box since the latter uses dynamic memory allocation and you'll need to use trait objects which have virtual function call as well. That said, compared to the equivalent code in C++ using std::variant and std::visit , looks like Rust in this scenario has more boilerplate coding involved, at least for me (I have not yet learned

来源： https://stackoverflow.com/questions/63662256/rust-if-an-enum-has-all-variants-derived-from-a-generic-struct-whats-the-best

来源： https://stackoverflow.com/questions/63662256/rust-if-an-enum-has-all-variants-derived-from-a-generic-struct-whats-the-best

来源： https://stackoverflow.com/questions/63662256/rust-if-an-enum-has-all-variants-derived-from-a-generic-struct-whats-the-best

来源： https://stackoverflow.com/questions/41129804/windows-variant-coercion-rules

来源： https://stackoverflow.com/questions/61298696/calling-operator-on-types-held-in-a-stdvariant