Re-implement move assignments.

The original swap approach leads to potential undefined behavior (reading
uninitialized memory) and results in unnecessary copying of data for static
storage.

Here we pass down the move assignment to the underlying storage.  Static
storage does a one-way copy, dynamic storage does a swap.

Modified the tests to no longer read from the moved-from matrix/tensor,
since that can lead to UB. Added a test to ensure we do not access
uninitialized memory in a move.

Fixes: #2119
This commit is contained in:
Antonio Sanchez
2021-03-05 12:54:26 -08:00
committed by Rasmus Munk Larsen
parent b8d1857f0d
commit 543e34ab9d
8 changed files with 62 additions and 17 deletions

View File

@@ -157,7 +157,7 @@ class Array
EIGEN_DEVICE_FUNC
Array& operator=(Array&& other) EIGEN_NOEXCEPT_IF(std::is_nothrow_move_assignable<Scalar>::value)
{
other.swap(*this);
Base::operator=(std::move(other));
return *this;
}
#endif

View File

@@ -278,7 +278,7 @@ class Matrix
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
Matrix& operator=(Matrix&& other) EIGEN_NOEXCEPT_IF(std::is_nothrow_move_assignable<Scalar>::value)
{
other.swap(*this);
Base::operator=(std::move(other));
return *this;
}
#endif

View File

@@ -508,8 +508,8 @@ class PlainObjectBase : public internal::dense_xpr_base<Derived>::type
EIGEN_DEVICE_FUNC
PlainObjectBase& operator=(PlainObjectBase&& other) EIGEN_NOEXCEPT
{
using std::swap;
swap(m_storage, other.m_storage);
_check_template_params();
m_storage = std::move(other.m_storage);
return *this;
}
#endif