Spurious error indication in IDE; program compiles fine

In a medium-large C++ code base, there are a few places where CLion marks code as invalid, but the code compiles just fine. In each case the error message was "Binary operator '<<' can't be applied to the expressions of type 'std::ostream' and [some other class]". I extracted a test case that shows three examples of this issue. The test case does nothing when executed, but it clearly shows the effect I am talking about, and is just under 100 lines, rather than the tens of thousands of lines in the original examples.

In this test case, making seemingly trivial changes will make the error indications go away. For example, collapsing the contents of namespace Value into its parent namespace will make one of the errors go away.

I am using CLion 2017.3.1 on 64-bit Ubuntu 16.04 LTS.