Implements the base class of most policy classes defining the narrow observer policies.

Requires: Nothing.

Namespace: BOOST_OUTCOME_V2_NAMESPACE::policy

Header: <boost/outcome/policy/base.hpp>

Protected member functions

Special

1. static void _ub(Impl &&)

   Special function which causes noticeable hard undefined behaviour.

Observers

1. static bool _has_value(Impl &&) noexcept

   Returns true if a value is present in the implementation passed in. Constexpr, never throws.

2. static bool _has_error(Impl &&) noexcept

   Returns true if an error is present in the implementation passed in. Constexpr, never throws.

3. static bool _has_exception(Impl &&) noexcept

   Returns true if an exception is present in the implementation passed in. Constexpr, never throws.

4. static bool _has_error_is_errno(Impl &&) noexcept

   Returns true if the error code in the implementation passed in has a domain or category matching that of POSIX errno. Constexpr, never throws.

5. static auto &&_value(Impl &&) noexcept

   Returns a reference to the value in the implementation passed in. Constexpr, never throws.

6. static auto &&_error(Impl &&) noexcept

   Returns a reference to the error in the implementation passed in. Constexpr, never throws.

7. static auto &&_exception(Impl &&) noexcept

   Returns a reference to the exception in the implementation passed in. Constexpr, never throws.

Modifiers

1. static void _set_has_value(Impl &&, bool) noexcept

   Sets whether the implementation has a value. Constexpr, never throws.

2. static void _set_has_error(Impl &&, bool) noexcept

   Sets whether the implementation has an error. Constexpr, never throws.

3. static void _set_has_exception(Impl &&, bool) noexcept

   Sets whether the implementation has an exception. Constexpr, never throws.

4. static void _set_has_exception(Impl &&, bool) noexcept

   Sets whether the implementation’s error code has a domain or category matching that of POSIX errno. Constexpr, never throws.

Public member functions

1. static void narrow_value_check(Impl &&) noexcept

   Observer policy performing hard UB if no value is present. Constexpr, never throws.

2. static void narrow_error_check(Impl &&) noexcept

   Observer policy performing hard UB if no error is present. Constexpr, never throws.

3. static void narrow_exception_check(Impl &&) noexcept

   Observer policy performing hard UB if no exception is present. Constexpr, never throws.