Conditionally-supported behavior (Using the GNU Compiler Collection (GCC))

Each implementation shall include documentation that identifies all conditionally-supported constructs that it does not support (C++0x 1.4).

Whether an argument of class type with a non-trivial copy constructor or destructor can be passed to ... (C++0x 5.2.2).
Such argument passing is supported, using the same pass-by-invisible-reference approach used for normal function arguments of such types.