Document that Result.unwrap prints the Err's value

[masklinn]

I saw that it was bounded by Show but the implication is no guarantee (and had only 0.10 to test, where this behavior has been added to 0.11)

[alexcrichton]

Could you tweak the documentation to say that instead of printing the task fails with E's Show implementation? You can suppress printing with set_stderr or redirect to any location.

[masklinn]

Sure. Maybe model the precise message after Option.expect's, e.g.

Fails if the value is an Err, with a custom failure message provided by the Err's value.

would that work?

Should I squash the new commit atop the old one?

[alexcrichton]

That sounds good to me! And yes, I'm a fan of squashing :)

[masklinn]

Here's a version with error messages matching that of Option.expect, I also added a Failure section title since that seems to be pretty common.

[steveklabnik]