Accessing cxx::expected which contains a value or error leads to UB if the contrary is accessed

[mossmaurice]

Required information

Operating system:
Ubuntu 20.04.3 LTS

Compiler version:
GCC 8.4.0

Observed result or behaviour:
Accessing cxx::expected which contains a value or error leads to UB if the contrary is accessed.

Expected result or behaviour:
Defined behaviour aka call to error handler via cxx::Expects.

Conditions where it occurred / Performed steps:

auto sut = expected<Foo, Bar>::create_value(VALID_VALUE);
auto foo = sut.get_error();
// or
auto sut = expected<Foo, Bar>::create_error(Bar::VALID_ERROR);
auto foo = sut.value();
sut->memberVariableOfFoo;