[boost] [quickbook] diagnosing a missing [endsect]?

Subject: [boost] [quickbook] diagnosing a missing [endsect]?
From: Peter Dimov (lists_at_[hidden])
Date: 2017-03-15 23:21:38

I just noticed a missing [endsect] in the middle of one of the .qbk files in 
the Core documentation. The main .qbk file contains

[include addressof.qbk]
[include checked_delete.qbk]
[include demangle.qbk]
[include enable_if.qbk]
[include explicit_operator_bool.qbk]
[include ignore_unused.qbk]
[include is_same.qbk]
[include lightweight_test.qbk]
[include no_exceptions_support.qbk]
[include noncopyable.qbk]
[include null_deleter.qbk]
[include ref.qbk]
[include scoped_enum.qbk]
[include swap.qbk]
[include typeinfo.qbk]

and in the middle of lightweight_test.qbk an [endsect] was missing. The end 
result of it was that the following includes went into the [section] opened 
in lightweight_test.qbk, as subsections. This wasn't noticeable from a 
cursory look so it went unnoticed for a while.

Is it worth diagnosing this problem in some way? We probably can't disallow 
unbalanced sections in an [include], but this could be a warning? (If 
someone pays it any attention, of course.)

Presumably, at the end of the file there'll be a [section] left open? This 
could be made an error so it'd be harder to miss.