* Construct from an unwrapped equivalent of the transformed type. */

Construct from string error message

Embeds a `nothing` in `M`.

* Invoke the failure state. * * Failing embeds a left value of `monoid<L>`'s identity element with * `monad<M>::pure`. */

Equivalent of function(std::nullptr_t)

* Function returning monoid<M>::id(). */

Simply creates an "empty" pointer.

Future representing `monoid<T>::id()`

TODO: constexpr c++14

* Lazily "computes" monoid<T>::id() */

Return `false`

Returns `true`

* Flatten a nested maybe. * * Works in the obvious way: if an inner maybe exists, it is returned; * otherwise `Nothing` is returned. */

* Flattens a set of sets. * * Preservation of relative order (from the perspective of depth-first * iteration of the original set of sets) is

Flattens nested Identities

Construct from underlying type