appender!(string[]).put(string) doesn't work

[David Held via Digitalmars-d-learn]

    auto data = appender!(string[]);
    ...
    data.put(someString);

source\colony.d(360): Error: template 
std.array.Appender(string[]).Appender.put does not match any function 
template declaration. Candidates are:
D:\D\dmd2\windows\bin\..\..\src\phobos\std\array.d(2251): 
std.array.Appender!(string[]).Appender.put(U)(U item) if (canPutItem!U)
D:\D\dmd2\windows\bin\..\..\src\phobos\std\array.d(2279): 
std.array.Appender!(string[]).Appender.put(Range)(Range items) if 
(canPutConstRange!Range)
D:\D\dmd2\windows\bin\..\..\src\phobos\std\array.d(2288): 
std.array.Appender!(string[]).Appender.put(Range)(Range items) if 
(canPutRange!Range)
source\colony.d(360): Error: template 
std.array.Appender!(string[]).Appender.put(U)(U item) if (canPutItem!U) 
cannot deduce template function from argument types !()(char[])

The example in the documentation implies that this should work fine. 
What am I missing?

Dave