/* Proposed SG14 status_code
-(C) 2018 - 2019 Niall Douglas <http://www.nedproductions.biz/> (5 commits)
+(C) 2018 - 2020 Niall Douglas <http://www.nedproductions.biz/> (5 commits)
File Created: Feb 2018
/*! A tag for an erased value type for `status_code<D>`.
Available only if `ErasedType` satisfies `traits::is_move_bitcopying<ErasedType>::value`.
*/
-template <class ErasedType, //
- typename std::enable_if<traits::is_move_bitcopying<ErasedType>::value, bool>::type = true>
+BOOST_OUTCOME_SYSTEM_ERROR2_TEMPLATE(class ErasedType) //
+BOOST_OUTCOME_SYSTEM_ERROR2_TREQUIRES(BOOST_OUTCOME_SYSTEM_ERROR2_TPRED(traits::is_move_bitcopying<ErasedType>::value))
struct erased
{
using value_type = ErasedType;
static constexpr bool value = true;
};
+#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ >= 8
// From http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4436.pdf
namespace impl
{
template <class T, class... Args> using get_make_status_code_result = decltype(make_status_code(std::declval<T>(), std::declval<Args>()...));
template <class... Args> using safe_get_make_status_code_result = test_apply<get_make_status_code_result, Args...>;
+
+#else
+
+ // ICE avoidance form for GCCs before 8. Note this form doesn't prevent recursive make_status_code ADL instantation,
+ // so in certain corner cases this will break. On the other hand, more useful than an ICE.
+ namespace impl
+ {
+ template <typename... Ts> struct make_void
+ {
+ using type = void;
+ };
+ template <typename... Ts> using void_t = typename make_void<Ts...>::type;
+ template <class...> struct types
+ {
+ using type = types;
+ };
+ template <typename Types, typename = void> struct make_status_code_rettype
+ {
+ using type = void;
+ };
+ template <typename... Args> using get_make_status_code_result = decltype(make_status_code(std::declval<Args>()...));
+ template <typename... Args> struct make_status_code_rettype<types<Args...>, void_t<get_make_status_code_result<Args...>>>
+ {
+ using type = get_make_status_code_result<Args...>;
+ };
+ } // namespace impl
+ template <class... Args> struct safe_get_make_status_code_result
+ {
+ using type = typename impl::make_status_code_rettype<impl::types<Args...>>::type;
+ };
+#endif
} // namespace detail
//! Trait returning true if the type is a status code.
{
}
+ // Used to work around triggering a ubsan failure. Do NOT remove!
+ constexpr const status_code_domain *_domain_ptr() const noexcept { return _domain; }
+
public:
//! Return the status code domain.
constexpr const status_code_domain &domain() const noexcept { return *_domain; }
BOOST_OUTCOME_SYSTEM_ERROR2_NODISCARD constexpr bool empty() const noexcept { return _domain == nullptr; }
//! Return a reference to a string textually representing a code.
- string_ref message() const noexcept { return (_domain != nullptr) ? _domain->_do_message(*this) : string_ref("(empty)"); }
+ BOOST_OUTCOME_SYSTEM_ERROR2_CONSTEXPR20 string_ref message() const noexcept
+ {
+ // Avoid MSVC's buggy ternary operator for expensive to destruct things
+ if(_domain != nullptr)
+ {
+ return _domain->_do_message(*this);
+ }
+ return string_ref("(empty)");
+ }
//! True if code means success.
- bool success() const noexcept { return (_domain != nullptr) ? !_domain->_do_failure(*this) : false; }
+ BOOST_OUTCOME_SYSTEM_ERROR2_CONSTEXPR20 bool success() const noexcept { return (_domain != nullptr) ? !_domain->_do_failure(*this) : false; }
//! True if code means failure.
- bool failure() const noexcept { return (_domain != nullptr) ? _domain->_do_failure(*this) : false; }
+ BOOST_OUTCOME_SYSTEM_ERROR2_CONSTEXPR20 bool failure() const noexcept { return (_domain != nullptr) ? _domain->_do_failure(*this) : false; }
/*! True if code is strictly (and potentially non-transitively) semantically equivalent to another code in another domain.
Note that usually non-semantic i.e. pure value comparison is used when the other status code has the same domain.
As `equivalent()` will try mapping to generic code, this usually captures when two codes have the same semantic
meaning in `equivalent()`.
*/
- template <class T> bool strictly_equivalent(const status_code<T> &o) const noexcept
+ template <class T> BOOST_OUTCOME_SYSTEM_ERROR2_CONSTEXPR14 bool strictly_equivalent(const status_code<T> &o) const noexcept
{
if(_domain && o._domain)
{
Firstly `strictly_equivalent()` is run in both directions. If neither succeeds, each domain is asked
for the equivalent generic code and those are compared.
*/
- template <class T> inline bool equivalent(const status_code<T> &o) const noexcept;
+ template <class T> BOOST_OUTCOME_SYSTEM_ERROR2_CONSTEXPR14 inline bool equivalent(const status_code<T> &o) const noexcept;
#if defined(_CPPUNWIND) || defined(__EXCEPTIONS) || defined(BOOST_OUTCOME_STANDARDESE_IS_IN_THE_HOUSE)
//! Throw a code as a C++ exception.
BOOST_OUTCOME_SYSTEM_ERROR2_NORETURN void throw_exception() const
#if __cplusplus >= 201400 || _MSC_VER >= 1910 /* VS2017 */
//! Return a reference to the `value_type`.
- constexpr value_type &value() & noexcept { return this->_value; }
+ constexpr value_type &value() &noexcept { return this->_value; }
//! Return a reference to the `value_type`.
- constexpr value_type &&value() && noexcept { return static_cast<value_type &&>(this->_value); }
+ constexpr value_type &&value() &&noexcept { return static_cast<value_type &&>(this->_value); }
#endif
//! Return a reference to the `value_type`.
constexpr const value_type &value() const &noexcept { return this->_value; }
{
};
template <class... Args>
- constexpr status_code_storage(_value_type_constructor /*unused*/, const status_code_domain *v, Args &&... args)
+ constexpr status_code_storage(_value_type_constructor /*unused*/, const status_code_domain *v, Args &&...args)
: _base(v)
, _value(static_cast<Args &&>(args)...)
{
/***** KEEP THESE IN SYNC WITH ERRORED_STATUS_CODE *****/
//! Implicit construction from any type where an ADL discovered `make_status_code(T, Args ...)` returns a `status_code`.
- template <class T, class... Args, //
- class MakeStatusCodeResult = typename detail::safe_get_make_status_code_result<T, Args...>::type, // Safe ADL lookup of make_status_code(), returns void if not found
- typename std::enable_if<!std::is_same<typename std::decay<T>::type, status_code>::value // not copy/move of self
- && !std::is_same<typename std::decay<T>::type, in_place_t>::value // not in_place_t
- && is_status_code<MakeStatusCodeResult>::value // ADL makes a status code
- && std::is_constructible<status_code, MakeStatusCodeResult>::value, // ADLed status code is compatible
-
- bool>::type = true>
- constexpr status_code(T &&v, Args &&... args) noexcept(noexcept(make_status_code(std::declval<T>(), std::declval<Args>()...))) // NOLINT
+ BOOST_OUTCOME_SYSTEM_ERROR2_TEMPLATE(class T, class... Args, //
+ class MakeStatusCodeResult = typename detail::safe_get_make_status_code_result<T, Args...>::type) // Safe ADL lookup of make_status_code(), returns void if not found
+ BOOST_OUTCOME_SYSTEM_ERROR2_TREQUIRES(BOOST_OUTCOME_SYSTEM_ERROR2_TPRED(!std::is_same<typename std::decay<T>::type, status_code>::value // not copy/move of self
+ && !std::is_same<typename std::decay<T>::type, in_place_t>::value // not in_place_t
+ && is_status_code<MakeStatusCodeResult>::value // ADL makes a status code
+ && std::is_constructible<status_code, MakeStatusCodeResult>::value)) // ADLed status code is compatible
+ constexpr status_code(T &&v, Args &&...args) noexcept(noexcept(make_status_code(std::declval<T>(), std::declval<Args>()...))) // NOLINT
: status_code(make_status_code(static_cast<T &&>(v), static_cast<Args &&>(args)...))
{
}
//! Implicit construction from any `quick_status_code_from_enum<Enum>` enumerated type.
- template <class Enum, //
- class QuickStatusCodeType = typename quick_status_code_from_enum<Enum>::code_type, // Enumeration has been activated
- typename std::enable_if<std::is_constructible<status_code, QuickStatusCodeType>::value, // Its status code is compatible
-
- bool>::type = true>
+ BOOST_OUTCOME_SYSTEM_ERROR2_TEMPLATE(class Enum, //
+ class QuickStatusCodeType = typename quick_status_code_from_enum<Enum>::code_type) // Enumeration has been activated
+ BOOST_OUTCOME_SYSTEM_ERROR2_TREQUIRES(BOOST_OUTCOME_SYSTEM_ERROR2_TPRED(std::is_constructible<status_code, QuickStatusCodeType>::value)) // Its status code is compatible
constexpr status_code(Enum &&v) noexcept(std::is_nothrow_constructible<status_code, QuickStatusCodeType>::value) // NOLINT
: status_code(QuickStatusCodeType(static_cast<Enum &&>(v)))
{
}
//! Explicit in-place construction. Disables if `domain_type::get()` is not a valid expression.
template <class... Args>
- constexpr explicit status_code(in_place_t /*unused */, Args &&... args) noexcept(std::is_nothrow_constructible<value_type, Args &&...>::value)
+ constexpr explicit status_code(in_place_t /*unused */, Args &&...args) noexcept(std::is_nothrow_constructible<value_type, Args &&...>::value)
: _base(typename _base::_value_type_constructor{}, &domain_type::get(), static_cast<Args &&>(args)...)
{
}
//! Explicit in-place construction from initialiser list. Disables if `domain_type::get()` is not a valid expression.
template <class T, class... Args>
- constexpr explicit status_code(in_place_t /*unused */, std::initializer_list<T> il, Args &&... args) noexcept(std::is_nothrow_constructible<value_type, std::initializer_list<T>, Args &&...>::value)
+ constexpr explicit status_code(in_place_t /*unused */, std::initializer_list<T> il, Args &&...args) noexcept(std::is_nothrow_constructible<value_type, std::initializer_list<T>, Args &&...>::value)
: _base(typename _base::_value_type_constructor{}, &domain_type::get(), il, static_cast<Args &&>(args)...)
{
}
`value_type` is trivially copyable or move bitcopying, and `sizeof(status_code) <= sizeof(status_code<erased<>>)`.
Does not check if domains are equal.
*/
- template <class ErasedType, //
- typename std::enable_if<detail::type_erasure_is_safe<ErasedType, value_type>::value, bool>::type = true>
+ BOOST_OUTCOME_SYSTEM_ERROR2_TEMPLATE(class ErasedType) //
+ BOOST_OUTCOME_SYSTEM_ERROR2_TREQUIRES(BOOST_OUTCOME_SYSTEM_ERROR2_TPRED(detail::type_erasure_is_safe<ErasedType, value_type>::value))
constexpr explicit status_code(const status_code<erased<ErasedType>> &v) noexcept(std::is_nothrow_copy_constructible<value_type>::value)
: status_code(detail::erasure_cast<value_type>(v.value()))
{
}
//! Return a reference to a string textually representing a code.
- string_ref message() const noexcept { return this->_domain ? string_ref(this->domain()._do_message(*this)) : string_ref("(empty)"); }
+ BOOST_OUTCOME_SYSTEM_ERROR2_CONSTEXPR20 string_ref message() const noexcept
+ {
+ // Avoid MSVC's buggy ternary operator for expensive to destruct things
+ if(this->_domain != nullptr)
+ {
+ return string_ref(this->domain()._do_message(*this));
+ }
+ return string_ref("(empty)");
+ }
};
namespace traits
status_code &operator=(const status_code &) = delete;
//! Move assignment
status_code &operator=(status_code &&) = default; // NOLINT
- ~status_code()
+ BOOST_OUTCOME_SYSTEM_ERROR2_CONSTEXPR20 ~status_code()
{
if(nullptr != this->_domain)
{
}
//! Return a copy of the erased code by asking the domain to perform the erased copy.
- status_code clone() const
+ BOOST_OUTCOME_SYSTEM_ERROR2_CONSTEXPR20 status_code clone() const
{
if(nullptr == this->_domain)
{
/***** KEEP THESE IN SYNC WITH ERRORED_STATUS_CODE *****/
//! Implicit copy construction from any other status code if its value type is trivially copyable and it would fit into our storage
- template <class DomainType, //
- typename std::enable_if<std::is_trivially_copyable<typename DomainType::value_type>::value //
- && detail::type_erasure_is_safe<value_type, typename DomainType::value_type>::value,
- bool>::type = true>
+ BOOST_OUTCOME_SYSTEM_ERROR2_TEMPLATE(class DomainType) //
+ BOOST_OUTCOME_SYSTEM_ERROR2_TREQUIRES(BOOST_OUTCOME_SYSTEM_ERROR2_TPRED(std::is_trivially_copyable<typename DomainType::value_type>::value //
+ &&detail::type_erasure_is_safe<value_type, typename DomainType::value_type>::value))
constexpr status_code(const status_code<DomainType> &v) noexcept // NOLINT
- : _base(typename _base::_value_type_constructor{}, &v.domain(), detail::erasure_cast<value_type>(v.value()))
+ : _base(typename _base::_value_type_constructor{}, v._domain_ptr(), detail::erasure_cast<value_type>(v.value()))
{
}
//! Implicit move construction from any other status code if its value type is trivially copyable or move bitcopying and it would fit into our storage
- template <class DomainType, //
- typename std::enable_if<detail::type_erasure_is_safe<value_type, typename DomainType::value_type>::value, bool>::type = true>
+ BOOST_OUTCOME_SYSTEM_ERROR2_TEMPLATE(class DomainType) //
+ BOOST_OUTCOME_SYSTEM_ERROR2_TREQUIRES(BOOST_OUTCOME_SYSTEM_ERROR2_TPRED(detail::type_erasure_is_safe<value_type, typename DomainType::value_type>::value))
BOOST_OUTCOME_SYSTEM_ERROR2_CONSTEXPR14 status_code(status_code<DomainType> &&v) noexcept // NOLINT
- : _base(typename _base::_value_type_constructor{}, &v.domain(), detail::erasure_cast<value_type>(v.value()))
+ : _base(typename _base::_value_type_constructor{}, v._domain_ptr(), detail::erasure_cast<value_type>(v.value()))
{
v._domain = nullptr;
}
//! Implicit construction from any type where an ADL discovered `make_status_code(T, Args ...)` returns a `status_code`.
- template <class T, class... Args, //
- class MakeStatusCodeResult = typename detail::safe_get_make_status_code_result<T, Args...>::type, // Safe ADL lookup of make_status_code(), returns void if not found
- typename std::enable_if<!std::is_same<typename std::decay<T>::type, status_code>::value // not copy/move of self
- && !std::is_same<typename std::decay<T>::type, value_type>::value // not copy/move of value type
- && is_status_code<MakeStatusCodeResult>::value // ADL makes a status code
- && std::is_constructible<status_code, MakeStatusCodeResult>::value, // ADLed status code is compatible
- bool>::type = true>
- constexpr status_code(T &&v, Args &&... args) noexcept(noexcept(make_status_code(std::declval<T>(), std::declval<Args>()...))) // NOLINT
+ BOOST_OUTCOME_SYSTEM_ERROR2_TEMPLATE(class T, class... Args, //
+ class MakeStatusCodeResult = typename detail::safe_get_make_status_code_result<T, Args...>::type) // Safe ADL lookup of make_status_code(), returns void if not found
+ BOOST_OUTCOME_SYSTEM_ERROR2_TREQUIRES(BOOST_OUTCOME_SYSTEM_ERROR2_TPRED(!std::is_same<typename std::decay<T>::type, status_code>::value // not copy/move of self
+ && !std::is_same<typename std::decay<T>::type, value_type>::value // not copy/move of value type
+ && is_status_code<MakeStatusCodeResult>::value // ADL makes a status code
+ && std::is_constructible<status_code, MakeStatusCodeResult>::value)) // ADLed status code is compatible
+ constexpr status_code(T &&v, Args &&...args) noexcept(noexcept(make_status_code(std::declval<T>(), std::declval<Args>()...))) // NOLINT
: status_code(make_status_code(static_cast<T &&>(v), static_cast<Args &&>(args)...))
{
}
- //! Implicit construction from any `quick_status_code_from_enum<Enum>` enumerated type.
- template <class Enum, //
- class QuickStatusCodeType = typename quick_status_code_from_enum<Enum>::code_type, // Enumeration has been activated
- typename std::enable_if<std::is_constructible<status_code, QuickStatusCodeType>::value, // Its status code is compatible
- bool>::type = true>
+ //! Implicit construction from any `quick_status_code_from_enum<Enum>` enumerated type.
+ BOOST_OUTCOME_SYSTEM_ERROR2_TEMPLATE(class Enum, //
+ class QuickStatusCodeType = typename quick_status_code_from_enum<Enum>::code_type) // Enumeration has been activated
+ BOOST_OUTCOME_SYSTEM_ERROR2_TREQUIRES(BOOST_OUTCOME_SYSTEM_ERROR2_TPRED(std::is_constructible<status_code, QuickStatusCodeType>::value)) // Its status code is compatible
constexpr status_code(Enum &&v) noexcept(std::is_nothrow_constructible<status_code, QuickStatusCodeType>::value) // NOLINT
: status_code(QuickStatusCodeType(static_cast<Enum &&>(v)))
{
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