I was about to comment the same. Also happened in absl (Google's alternative to the STL template library for C++ which started its life as GTL) -- when changing the default hash function for unordered maps it led to breaking changes in both test and production code that had depended on it.
OrderedDict types are nice sometimes but shouldn't be the default behavior, IMO.
There are good reasons for the second point (about default/named parameters) -- any calling code is making some assumptions based on that default value so there's a risk it can't be changed or added to. If you really want a default value, make a wrapper function for it. In the example it would be a simple matter of defining ReplaceAll with three arguments that always passes -1 to Replace(...)
OrderedDict types are nice sometimes but shouldn't be the default behavior, IMO.
There are good reasons for the second point (about default/named parameters) -- any calling code is making some assumptions based on that default value so there's a risk it can't be changed or added to. If you really want a default value, make a wrapper function for it. In the example it would be a simple matter of defining ReplaceAll with three arguments that always passes -1 to Replace(...)