The table here https://gcc.gnu.org/projects/cxx0x.html states that N2660 is in GCC 4.3. However, the release specific tables 4.3 - 4.7 have the availability marked as "No". Not until 4.8 does the table have the ability marked as "Yes" in the table. https://gcc.gnu.org/gcc-4.3/cxx0x_status.html https://gcc.gnu.org/gcc-4.7/cxx0x_status.html https://gcc.gnu.org/gcc-4.8/cxx0x_status.html Which table(s) are correct?