foreach my $string (
    'i am the very model of a modern major-general.',
    'this is one sentence.  this is two.',
    'foo bar',
    'outside parens (inside them)',
    'outside brackets [inside them], now braces {inside}',
) {
    (my $two_capture = $string) =~ s/ (^|[-\s(])  (\w) / $1 . uc $2 /egx;
    (my $boundary    = $string) =~ s/ \b          (\w) /      uc $1 /egx;
    (my $alternation = $string) =~ s/ (-|\s|^|\() (. ) / $1 . uc $2 /egx;

    print(
        "string:      $string\n",
        "two_capture: $two_capture\n",
        "boundary:    $boundary\n",   
        "alternation: $alternation\n",
        "\n"
    );
}