[odb-users] Issue with std::weak_ptr in Bidirectional Relationship with ODB Classes

[Boris Kolpackov]

xuewen wang <xuewen.ok at gmail.com> writes:

> /usr/include/c++/10/bits/shared_ptr.h:707:30:   required by substitution of
> ‘template<class _Yp, class>
> std::weak_ptr<database::IrradianceProfileDb>::weak_ptr(const
> std::weak_ptr<_Tp>&) [with _Yp = database::IrradianceProfileDb;
> <template-parameter-1-2> = <missing>]’

This suggests that the definition is needed when calling the
weak_ptr's copy constructor (and likely other functions, like
the destructor). I suggest that you try to move definitions of
all your functions in the two classes after both are defined.
Something along these lines:

class B;

class A
{
  std::weak_ptr<B> b;

  A (const A&);
};

class B
{
  std::shared_ptr<A> b;
};

inline A::A (const A&)
  : ...
{
}

If you still cannot make it work, please provide a minimal but
complete reproducer (header file plus the ODB compiler command
line to compile it).