emacs regex help

Okay, this should be s开发者_StackOverflow中文版uper easy, I must be doing something dumb.

I've got this:

double foo3;

I want to replace it with:

archiver & BOOST_SERIALIZATION(foo3);

I do this:

M-x query-replace-regxp RET double \(a-z0-9+\) RET archiver & BOOST_SERIALIZATION(\1)

Emacs says 0 matches.

You mist the List Operator:

double \([a-z0-9]+\)