Re: Calling a class constructor as a function on input arguments

[tye]

This sounds like a job for anonymous subs:

    my %constructor= {
        MSWin32 => sub { FTP::Session::Win32->new( @_ ) },
        HPUX => sub { FTP::Session::HPUX->new( @_ ) },
    }
    my $ctor= $constructor{$^O};
    die "No constructor for $^O"   if  ! $ctor;
    my $session= $ctor->( ... );
    # Old Perl requires:  $session= &$ctor( ... );

The next best thing is UNIVERSAL::can(), which returns a reference to a named method. But then you need to cache each class name so that you can pass that in to the sub that you got a reference to:

    my %class= {
        MSWin32 => "FTP::Session::Win32",
        HPUX => "FTP::Session::HPUX",
    }
    my %constructor= {
        MSWin32 => FTP::Session::Win32->can("new"),
        HPUX => FTP::Session::HPUX->can( "new" ),
    }
    my $ctor= $constructor{$^O};
    die "No constructor for $^O"   if  ! $ctor;
    my $session= $ctor->( $class{$^O}, ... );
    # Old Perl requires:  $session= &$ctor( $class{$^O}, ... );