optional lite - A C++17-like optional, a nullable object for C++98, C++11 and later in a single-file header-only library

Monad, Functional Programming features for Golang

Monad/MonadIO, Handler, Coroutine/doNotation, Functional Programming features for Rust

Functional Programming for EcmaScript(Javascript)

Replacement for std::optional with efficient memory usage and additional features.

optional bare - A simple version of a C++17-like optional for default-constructible, copyable types, for C++98 and later in a single-file header-only library

Proof that java Optional is not a functor, but vavr is.

Commons module for DiDi modules. Implemented submodules: Optional (sync + async).