Aha! Thanks for the cogent explanation. Along with some advice from bart on the chatterbox, I came up with the following proof-of-concept solution.

#! /usr/local/bin/perl -l

package P;

sub new {
    my $class = shift;
    my $mod   = shift;
    eval "use $mod ()";
    my $self = {};
    if ($@) {
        $self->{_time_func} = sub { time };
    }
    else {
        $self->{_time_func} = sub { Time::HiRes::time() };
    }
    return bless $self, 'P'
}

package main;

my $p = P->new( shift || 'Time::HiRes' );

print $p->{_time_func}->();
sleep 2;
print $p->{_time_func}->();

[download]

You can run this, and if T::HR is installed, you get fractional times. Pass it junk on the command line, and then T::HR is not loaded (which simulates what happens on an installation that lacks it, or fails to load) and integer seconds come out.

In the real world, the _time_func business will be hidden from the user, they just get back fractional seconds, or not.

• another intruder with the mooring in the heart of the Perl

In reply to Re^2: Importing Time::HiRes::time at run-time (and failing) by grinder
in thread Importing Time::HiRes::time at run-time (and failing) by grinder

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