B0_std.FutSourceFuture values.
A future is an undetermined value that becomes determined at an an arbitrary point in the future. The future acts as a placeholder for the value while it is undetermined.
The type for futures with values of type 'a.
create () is (f, set) with f the future value and set the function to set it. The latter can be called only once, Invalid_argument is raised otherwise.
await f k waits for f to be determined and continues with k v with v the value of the future. If the future never determines k is not invoked. k must not raise.
of_list fs determines with the values of all fs, in the same order.