Class Peek

gil/gil.impl.hpp:443–447

};

template <auto expr> struct Peek {
  template <typename Runtime>
  using Eval = tfunc::Get<typename Runtime::Stdin, Eval<Runtime, expr>::value,
                          type::None>;
};

template <auto expr> struct Len {
  template <typename Runtime> using Eval = tfunc::Len<Eval<Runtime, expr>>;