Incompatible type of std::imag function

[Gabriel Dos Reis]

Paolo Carlini <pcarlini@suse.de> writes:

| (*) Note, however, that now that TR1 is out, setters seem slightly
| better from the point of view of consisteny with TR1, 8.1.9: the
| additional overloads cannot return by reference.

setters might be consitsnt with TR1, but, TR1 is wrong :-)

-- Gaby