@apfelbox I don't really understand your point.

The code is replacing namespace delimiters with whatever `DIRECTORY_SEPARATOR` happens to be.

If you imagine the class `\Some\Namespaced\Classname` being loaded.

Before is: `str_replace('\\', '/', '\\Some\\Namespaced') . '/'`
After is: `str_replace('\\', '/', '\\Some\\Namespaced\\')`

The result is the same with a smaller string processing overhead.