Lemme re-comment this for you: 
use strict;
sub This::Does::Not::Fail { };

# Rightly so because you've already notified Perl that
# this is a subroutine name.  It *knows* this identifier
# is a sub.  Thanks for pre-declaring it!
This::Does::Not::Fail;                 # rightly so

# This fails because you've given perl no contextual hints
# that this is a subroutine.  It might be... a filehandle!
# Or something else.  But you haven't pre-declared it 
# either.  This is a bareword (an identifier).
This::Will::Fail;                      # as we expect

# You haven't pre-declared this thing.
# *BUT* you did give perl a contextual hint that this is 
# indeed a subroutine.  This is essentially a *promise* 
# you've made to strict that at runtime, when this code is
# encountered, you'll have a subroutine with this name
# all ready to go.
It::Bothers::Me::That::This::Works (); # wassup with THAT?!

[download]
For that last point, there are other "promises" you can make and not just with parens. Some of these include: 
$obj->method;   # Either $obj class' method will exist or
                # AUTOLOAD had better take care of it later.
$a=foo Bar;     # Bar will have a foo()!  Or AUTOLOAD...etc.
&foo;           # Again, you've promised it will exist...

[download]

In reply to Re: non-barewords and use strict by clintp
in thread non-barewords and use strict by Solo

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.