value_ref(
    value_ref const&); (1)

value_ref(
    value_ref&&); (2)

value_ref(
    string_view s) noexcept; (3)

template<
    class T>
value_ref(
    T const& t) noexcept; (4)

template<
    class T>
value_ref(
    T&& t) noexcept; (5)

value_ref(
    bool b) noexcept; (6)

value_ref(
    std::initializer_list< value_ref > t) noexcept; (7)

value_ref(
    signed char t) noexcept; (8)

value_ref(
    short t) noexcept; (9)

value_ref(
    int t) noexcept; (10)

value_ref(
    long t) noexcept; (11)

value_ref(
    long long t) noexcept; (12)

value_ref(
    unsigned char t) noexcept; (13)

value_ref(
    unsigned short t) noexcept; (14)

value_ref(
    unsigned int t) noexcept; (15)

value_ref(
    unsigned long t) noexcept; (16)

value_ref(
    unsigned long long t) noexcept; (17)

value_ref(
    float t) noexcept; (18)

value_ref(
    double t) noexcept; (19)

value_ref(
    std::nullptr_t) noexcept; (20)