#### System Errors and Error Codes

When available, Asio can use the `std::error_code` and `std::system_error` classes for reporting errors. In this case, the names `asio::error_code` and `asio::system_error` will be typedefs for these standard classes.

System error support is automatically enabled for `g++` 4.6 and later, when the `-std=c++0x` or `-std=gnu++0x` compiler options are used. It may be disabled by defining `ASIO_DISABLE_STD_SYSTEM_ERROR`, or explicitly enabled for other compilers by defining `ASIO_HAS_STD_SYSTEM_ERROR`.