text: #include <stan/math/rev/scal.hpp>
  #include <gtest/gtest.h>
  
  template <typename... Ts>
  void expect_not_const() {
    using stan::is_constant_all;
    bool temp = is_constant_all<Ts...>::value;
    EXPECT_FALSE(temp);
  }
  
  TEST(MetaTraits, isConstantStruct) {
    expect_not_const<stan::math::var>();
    expect_not_const<stan::math::var, double>();
    expect_not_const<stan::math::var, double, stan::math::var>();
    expect_not_const<stan::math::var, double, double>();
    expect_not_const<stan::math::var, stan::math::var, stan::math::var,
                     stan::math::var, stan::math::var, double, double>();
  }
  