How is that possible? Sure you can redefine _, but that won't do any blessing at compile time.

Quite possible. My webapp is large, and runs within mod_perl, so I have an initialisation process which loads most required modules at the beginning. In my i18n class, which gets loaded as early as possible, I have this code:

    {
        no warnings 'redefine';

        sub compile_mode {
            *::_ = sub { i18n::String->new(@_) };
        }

        sub run_mode {
            *::_ = sub { $i18n::Current_Lang->maketext(@_) };
        }
    }

    BEGIN {
        compile_mode();
    }
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Once initialisation is finished, my loader calls i18n::run_mode. If I need to require any large modules that belong to my app during runtime, instead of using the require builtin, I call i18n::i18n_require('Module::Name'):

    sub i18n_require {
        my $original = my $path = shift;
        i18n::compile_mode();
        $path=~s{::}{/}g;

        my $error;
        eval {require $path.'.pm'}
         or $error = $@ || 'Unknown error';
        
        i18n::run_mode();

        die( sprintf( "Error loading '%s' at %s line %d:\n%s\n",
                      $original, (caller)[ 1, 2 ], $error
             )
        ) if $error;

        return $INC{$path};
    }
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I tried overriding UNIVERSAL::require, but certain modules outside my control didn't appreciate that. Anyway, doing it this way is explicit, and only a few characters more.