: Cannot implement with language itself. Need compiler support. Used C++ N STL
: Partially implemented with C++ N
: Implemented with C++ N
: Not yet implemented
| C++17 Features | Implemented in |
|---|---|
| Classes | |
| optional |  *  |
| bad_optional_access | ** |
| ss::hash<ss::optional> |  |
| nullopt_t | |
| Constants | |
| nullopt | |
| Functions | |
| Comparison | |
| operator== operator!= operator< operator<= operator> operator>= |
|
| Specialized algorithms | |
| ss::swap(ss::optional) | |
| make_optional | |
| C++20 Features | Implemented in |
|---|---|
| Functions | |
| Comparison | |
| operator<=> |  |
* Non-const member functions is not constexpr.
Move and copy constructors are not constexpr.
** Inherits from std::exception