The change from C++0x to C++11 allows all of C++11 functionality to be
used in OpenFOAM, in particular constructor delegation which avoids code
duplication or constructor helper functions. However, this also means a
change to the minimum gcc version supported which is now 4.7 rather than
4.5.
Note that gcc-4.7 does not support the entire C++11 standard but does
support all of the functionality currently needed for further OpenFOAM
development. The minimum gcc-version which supports the entire C++11
standard is 4.8 which is now the recommended minimum gcc version.
which may be optionally overridden by version-specific rules.
For example the default rules for gcc on GNU/Linux x86_64 are in the
wmake/rules/linux64Gcc directory. If there is a need to change any of
the rules for a specific version of gcc, e.g. gcc-4.8.4 the directory
wmake/rules/linux64Gcc48 may be created into which any of the language
files may be provided containing the rules to override the defaults.