inline static VALUE k_rational_p(VALUE x) { return f_kind_of_p(x, rb_cRational); }
inline static VALUE k_complex_p(VALUE x) { return f_kind_of_p(x, rb_cComplex); }
inline static VALUE k_float_p(VALUE x) { return f_kind_of_p(x, rb_cFloat); }
inline static VALUE k_bignum_p(VALUE x) { return f_kind_of_p(x, rb_cBignum); }
inline static VALUE k_fixnum_p(VALUE x) { return f_kind_of_p(x, rb_cFixnum); }
inline static VALUE k_numeric_p(VALUE x) { return f_kind_of_p(x, rb_cNumeric); }
inline static VALUE k_integer_p(VALUE x) { return f_kind_of_p(x, rb_cInteger); }