class state_holder<T, false> filter¶

constexpr state_holder()                    = delete

constexpr state_holder(const state_holder&) = default

constexpr state_holder(state_holder&&)      = default

constexpr state_holder(T state) noexcept : s(std::move(state)) { … }

constexpr state_holder(std::reference_wrapper<T> state)       = delete

constexpr state_holder(std::reference_wrapper<const T> state) = delete

constexpr state_holder(state_holder<T, true> stateless) : s(*stateless) { … }

T s

const T* operator->() const

T* operator->()

const T& operator*() const

T& operator*()