Overload set ok

template<class R>
std::enable_if<grammar::is_rule<R>::value>::type
ok(
    const R& r,
    core::string_view s);
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template<
    class R,
    class V>
std::enable_if<grammar::is_rule<R>::value>::type
ok(
    const R& r,
    core::string_view s,
    const V& v);
  » more...