Kamil Kukura <kamk at volny.cz> wrote:
	I found in String>>fromString:
	"Answer an instance of me that is a copy of the argument, aString."
	
	Well, if "me" is not pure String but something derived, the above is not
	true.
	(DerivedString fromString: 'hello world') className "gives String"
	
	Fortunately ('hello world' as: DerivedString) works.
	
The method body reads
    ^aString copyFrom: 1 to: aString size
which boils down to
    (aString species new: aString size)
        replaceFrom: 1 to: aString size with: aString startingAt: 1

If the method body were to read
    ^(self new: aString size)
	replaceFrom: 1 to: aString size with: aString startingAt: 1

then this would agree with the method comment AND be slightly faster.