To be useful, option types and tuples need language support. C++ doesn't have it.
Similarly, to be useful, futures need runtime support i.e. asynchronous I/O. They also need language support like async-await, to generate these state machines. C++ has none of them.
The standard library still does not really support Unicode, people need third-party libraries like ICU just to manipulate strings: https://stackoverflow.com/q/42946335/126995
The streams from the standard library are broken beyond repair, I avoid them at all costs: https://www.moria.us/articles/iostream-is-hopelessly-broken/ Even <stdio.h> C header is much better abstraction, despite 50 years old.
To be useful, option types and tuples need language support. C++ doesn't have it.
Similarly, to be useful, futures need runtime support i.e. asynchronous I/O. They also need language support like async-await, to generate these state machines. C++ has none of them.
The standard library still does not really support Unicode, people need third-party libraries like ICU just to manipulate strings: https://stackoverflow.com/q/42946335/126995