Most mind-blowing C++ hack you've ever seen?
- by sblom
In the same spirit as the "Hidden features of X?" series, what are the most mind-blowingly well-executed "I didn't even think the language could do that!" hacks that you've ever seen in C++.
For example, my recent favorite is an implementation of the "operator" --> for pre-C++0x lambdas.
Another fantastic example is Multi-dimensional analog literals.
(Note: this is a community wiki question to avoid the appearance of reputation-whoring.)