Compile Errors VS2019

[fredlangva]

Getting the following error message for some of the Foundation files when building bsf:
binary '=': no operator found which takes a right-hand operand of type 'const std::pair<const K,V>' (or there is no acceptable conversion)
BsSkeleton
BsMeshImportOptions
BsAnimationClip
BsAnimationManager
BsAnimation
BsCAnimation