Thread: Is it possible to set/get user data to HANDLE/pthread_t?

Every attempt to find the information on the net just keeps coming up with irrelevant results around pthread_create() instead of say pthread_get_ud( thread )/pthread_set_ud( thread, ud ), I would prefer being able to get the final argument that gets passed onto the thread but no matter what I search it doesn't seem to be a thing despite it being such an obvious feature to need, just like windows, gc objects & others need.

Edit: To be clear it's these sort of actions I'd like to do something similar to:

Code:

glfwSetWindowUserPointer( Win->handle, Win );
...
void	onClosed( GLFWwindow *handle )
{
	pawWIN Win = glfwGetWindowUserPointer( handle );
	if ( Win->onClosedCB )
		Win->onClosedCB( Win );
}

Where all I have is the source api's reference to begin with