I can confirm that this is true in C++ (or at least the common implementations), as required by IEEE. In particular, this means that sorting a container includi

I can confirm that this is true in C++ (or at least the common implementations), as required by IEEE. In particular, this means that sorting a container including NaNs is undefined behavior (since typical sorting algorithms rely on the property that for any x and y, exactly one of x < y, y < x, or x = y is true).