str =~ <span class="hljs-regexp">/^(?:foo)$/</span> str =~ <span class="hljs-regexp">%r{foo|bar|buz$}</span> str =~ <span class="hljs-regexp">%r!foo|bar$!</span> str =~ <span class="hljs-regexp">%r[foo|bar$]</span> str =~ <span class="hljs-regexp">%r(\(foo|bar\)$)</span>