Exception transparency

[Paulo Levi]

Why is it not workable? Do programmers have trouble understanding that they
can't use private methods outside of their class to give a foolish example?
Why would they have problems understanding that they can only use "pure"
methods in the body of a pure function -recursive obvs? (aside, here you can
see why constructors, and SAM types are still useful, mark a method as pure,
but leave the constructor to deal with the impurity).

Seems like the most elegant solution, and frankly almost a requirement for
that the new parallel api's if they are to maintain a little sanity. The
alternative is to retrofit it later if the concept becomes available, that
will break code, and thus be used as a excuse to do nothing, as usual.