That's the part that confuses me. What does the "class or object method?" check in the constructor have to do with the "method or function call?" question?

I think these are two different things altogether, but the original post and your previous comment here make me wonder if you think they're different.

That's the part that confuses me. What does the "class or object method?" check in the constructor have to do with the "method or function call?" question?

Because a common idiom used to "solve" the "class or object method?" question, can lead to odd behavior when a constructor is called as a function and not a method. Sure, in a perfect world that should never happen, but we dont live in a perfect world, and it would be niave to think your code would execute in a perfect world. Of course, you could also just not care, if they use it wrong, you absolve yourself of all responsability, it's their fault. But I am really talking about defensive coding practices here, ways to strengthen your code in real world scenarios so that it acts as expected in all situations, even those of incorrect usage.

I think these are two different things altogether, but the original post and your previous comment here make me wonder if you think they're different.

They are different things conceptually, but in reality they are 2 different "facets" of the same code. One the intended usage, the other, the un-indentend usage. Again, I am talking defensive coding here, if you don't care what happens when someone mis-uses your code, then this doesn't matter. Personally, I do care.

-stvn

Because a common idiom used to "solve" the "class or object method?" question, can lead to odd behavior when a constructor is called as a function and not a method.

I disagree:

#!/usr/bin/perl -w

use strict;

use Test::More tests => 2;

package Foo;

sub new
{
    my $class = shift;
    bless {}, $class;
}

sub test
{
    1;
}

package Bar;

sub new
{
    my $class = shift;
    $class    = ref( $class ) || $class;
    bless {}, $class;
}

sub test
{
    1;
}

package main;

sub test
{
    0;
}

my $foo = Foo::new();
ok( $foo->test() );

my $bar = Bar::new();
ok( $bar->test() );
[download]

That's the same behavior regardless of the "class or object?" check. This leads me to conclude that that check has no bearing on the behavior. What leads you to believe otherwise?