In ubuntu12.04, the gcc4.6/g++4.6 version is reduced to gcc4.4/g++4.4.

reduce Ubuntu Central GCC and g++ version of

The gcc/g++ in Ubuntu 12.04 are all 4.6, dropping it to 4.4.

The procedure is as follows:

One, reduce the GCC version

1. $sudo Apt-get Install gcc-4.4

2, $sudo update-alternatives--INSTALL/USR/BIN/GCC gcc/usr/bin/gcc-4.4 40 (where "40" is the priority, the higher the value the higher the priority)

3, $sudo update-alternatives--INSTALL/USR/BIN/GCC gcc/usr/bin/gcc-4.6 60 (This machine comes with a set of 60 higher priority)

4, select the system default GCC

$sudo update-alternatives--config gcc

Selection	Path	priority	Status
* 0	/usr/bin/gcc-4.6		Auto mode
1	/usr/bin/gcc-4.4		Manual mode
2	/usr/bin/gcc-4.6		Manual mode

The default system with the highest priority, here we choose 1.

Second, reduce the g++ version

1. $sudo Apt-get Install g++-4.4

2, $sudo update-alternatives--install/usr/bin/g++ g++/usr/bin/g++-4.4 40 (here "40" is the priority, the higher the value the higher the priority)

3, $sudo update-alternatives--install/usr/bin/g++ g++/usr/bin/g++-4.6 60 (This machine comes with a set of 60 higher priority)

4, select the system default g++

$sudo update-alternatives--config g++

Selection	Path	priority	Status
* 0	/usr/bin/g++-4.6		Auto mode
1	/usr/bin/g++-4.4		Manual mode
2	/usr/bin/g++-4.6		Manual mode

The default system with the highest priority, here we choose 1.

Add: Switch with update-alternatives--config command if you want to change to a higher version at any time

In ubuntu12.04, the gcc4.6/g++4.6 version is reduced to gcc4.4/g++4.4.