Try it again with parens() after the name.... Your problem is that the symbol is being misinterpreted at compile time.

Spot on. Thanks.

---

Examine what is said, not who speaks.

Silence betokens consent.

Love the truth but pardon error.

You forgot to wrap in BEGIN {}.

#! perl -slw
#use HTTP::Status;
BEGIN {
require HTTP::Status; import HTTP::Status;
}

print RC_FORBIDDEN;
__DATA__
P:\test>test4        ## This is with c<use>
403

P:\test>test4        ## This is with require/import but no BEGIN
Name "main::RC_FORBIDDEN" used only once: possible typo at P:\test\tes
+t4.pl line 5.
print() on unopened filehandle RC_FORBIDDEN at P:\test\test4.pl line 5
+.

P:\test>test4        ## This is with require/import inside BEGIN
403
[download]

Updated to add complete code listing with output.

You forgot to wrap in BEGIN {}

No, that was deliberate. There would be no point in not using use if I did. The whole point is to defer the loading of the module until and if it is needed.

As constants are subs, and Perl allows you to call a sub that hasn't been declared yet, it is possible to use the constants in your code prior to them having been loaded. The bit I was missing, as merlyn pointed out above, is that it won't be recognised as a constant sub without having been previously declared or, I use the brackets().

---

Examine what is said, not who speaks.

Silence betokens consent.

Love the truth but pardon error.

No, that was deliberate. There would be no point in not using use if I did. The whole point is to defer the loading of the module until and if it is needed.

That's exactly the problem. Some of the benefits of "use"ing a module can only be observed when it is done at compile time. This is particularly important when prototypes are involved. For example, the Test::Exception module uses prototypes to allow you to use this syntax:

dies_ok {$foo->method1} 'expecting to die'; For one of my modules, I wanted to use Test::Exception in an eval so that I could skip the tests if Test::Exception was not installed. It didn't work (with the syntax shown above) until I wrapped the eval in a BEGIN block.

I overlooked that this was about conditionally loading the module somewhere between the OP and the post about HTTP::Status.

#! perl -slw

# This would normally be updated based on some condition in the code.
my $condition = 0;

# possibly very many lines of code go here

# Faking a condition in the code...
$condition ||= shift @ARGV;

if ($condition) {
  require HTTP::Status;
  import HTTP::Status;
  print RC_FORBIDDEN();  # as merlyn pointed out, we need to give the 
+parser a clue
}

__END__
P:\test>test4 0

P:\test>test4 1
403
[download]

This was really for my benefit and no one elses.