sub smartmatch {
    die 'smart' unless 'Germany' ~~ @countries;
    die 'smart' if     'Foo'     ~~ @countries;

}
__END__
           Rate   grep  first  smart  regex   hash
grep     7587/s     --   -17%   -58%   -83%  -100%
first    9135/s    20%     --   -50%   -79%  -100%
smart   18101/s   139%    98%     --   -59%   -99%
regex   43840/s   478%   380%   142%     --   -99%
hash  3508785/s 46146% 38312% 19285%  7904%     --