[boost] [optional] Doc edits

From: David B. Held (dheld_at_[hidden])
Date: 2003-03-14 13:10:52

Under "A note about optional<bool>" is the line:

    Second, optional<> provides and implicit conversion to bool.

Of course, it should be "an".  An even subtler nitpick is that in the
line:

    First, it is functionally similar to a tristate boolean (false,
    maybe,true) -such as boost::tribool-, except that in a tristate
    boolean, the maybe state represents a valid value, unlike the
    corresponding state of an uninitialized optional<bool>.

I think two hyphens should be used for the em-dashes (or the
actual em-dash character, which is probably not portable).  Also,
the comma after the em-dash is probably not necessary (even
though it would be if the parenthetical phrase were not present).

Otherwise, the documentation looks great!

Dave