Defining unconstrained mongo::operator<< functions as we do in sdam_test_base.h carries a significant risk of One Definition Rule violations. These are motivated entirely by a desire to be interoperable with ASSERT macros. I encountered them in SERVER-50516. I believe they are the only ones of their kind, because a previous sweep removed a few of the other unconstrained operator<< that were around the codebase.

We can work around the need for these by introducing a wrapper that provides a customized streaming operator to its argument.