Eroare de compilare: main.cpp:9:20: error: 'variant' in namespace 'std' does not name a template type 9 | using Token = std::variant<Operator, int>; | ^~~~~~~ main.cpp:9:15: note: 'std::variant' is only available from C++17 onwards 9 | using Token = std::variant<Operator, int>; | ^~~ main.cpp:26:13: error: 'Token' was not declared in this scope 26 | std::vector<Token> tokenize(const std::string &str) { | ^~~~~ main.cpp:26:18: error: template argument 1 is invalid 26 | std::vector<Token> tokenize(const std::string &str) { | ^ main.cpp:26:18: error: template argument 2 is invalid main.cpp: In function 'int tokenize(const string&)': main.cpp:27:17: error: 'Token' was not declared in this scope 27 | std::vector<Token> tokens; | ^~~~~ main.cpp:27:22: error: template argument 1 is invalid 27 | std::vector<Token> tokens; | ^ main.cpp:27:22: error: template argument 2 is invalid main.cpp:29:10: error: 'optional' is not a member of 'std' 29 | std::optional<int> num_builder = {}; | ^~~~~~~~ main.cpp:29:10: note: 'std::optional' is only available from C++17 onwards main.cpp:29:19: error: expected primary-expression before 'int' 29 | std::optional<int> num_builder = {}; | ^~~ main.cpp:32:13: error: 'num_builder' was not declared in this scope 32 | num_builder = num_builder.value_or(0) * 10 + (c - '0'); | ^~~~~~~~~~~ main.cpp:34:17: error: 'num_builder' was not declared in this scope 34 | if (num_builder.has_value()) { | ^~~~~~~~~~~ main.cpp:35:24: error: request for member 'push_back' in 'tokens', which is of non-class type 'int' 35 | tokens.push_back(num_builder.value()); | ^~~~~~~~~ main.cpp:41:24: error: request for member 'push_back' in 'tokens', which is of non-class type 'int' 41 | tokens.push_back(Add); | ^~~~~~~~~ main.cpp:44:24: error: request for member 'push_back' in 'tokens', which is of non-class type 'int' 44 | tokens.push_back(Sub); | ^~~~~~~~~ main.cpp:47:24: error: request for member 'push_back' in 'tokens', which is of non-class type 'int' 47 | tokens.push_back(Mul); | ^~~~~~~~~ main.cpp:50:24: error: request for member 'push_back' in 'tokens', which is of non-class type 'int' 50 | tokens.push_back(Div); | ^~~~~~~~~ main.cpp:53:24: error: request for member 'push_back' in 'tokens', which is of non-class type 'int' Non zero exit status: 1