因为想用template aliases特性，必须要GCC4.7.
又不想编译源代码，所以按照下面的方法安装。
sudo add-apt-repository ppa:Ubuntu-toolchain-r/test sudo apt-get update sudo apt-get install gcc-4.7 sudo apt-get install g++-4.7
如果Ubuntu 12.04 系统中存在多个版本的GCC，可以在CMake工程的顶层的CMakeLists.txt中配置：
cmake_minimum_required(VERSION 2.8.7) set(CMAKE_C_COMPILER "/usr/bin/gcc-4.7") set(CMAKE_CXX_COMPILER "/usr/bin/g++-4.7") project (sample) add_subdirectory(src bin)
然后在build目录下执行cmake .. 可以看到：chenshu@chenshu-beijing:~/work/research/tree/normal_tree/build$ cmake .. -- The C compiler identification is GNU -- The CXX compiler identification is GNU -- Check for working C compiler: /usr/bin/gcc-4.7 -- Check for working C compiler: /usr/bin/gcc-4.7 -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Check for working CXX compiler: /usr/bin/g++-4.7 -- Check for working CXX compiler: /usr/bin/g++-4.7 -- works -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Configuring done -- Generating done -- Build files have been written to: /home/chenshu/work/research/tree/normal_tree/build
不过我的方法不是CMake推荐的最佳方法，一共有三种方法可以参考：
How do I use a different compiler? [edit] Method 1: use environment variables For C and C++, set the CC and CXX environment variables. This method is not guaranteed to work for all generators. (Specifically, if you are trying to set Xcode's GCC_VERSION, this method confuses Xcode.) For example: CC=gcc-4.2 CXX=/usr/bin/g++-4.2 cmake -G "Your Generator" path/to/your/source [edit] Method 2: use cmake -D Set the appropriate CMAKE_FOO_COMPILER variable(s) to a valid compiler name or full path on the command-line using cmake -D. For example: cmake -G "Your Generator" -D CMAKE_C_COMPILER=gcc-4.2 -D CMAKE_CXX_COMPILER=g++-4.2 path/to/your/source [edit] Method 3 (avoid): use set() Set the appropriate CMAKE_FOO_COMPILER variable(s) to a valid compiler name or full path in a list file using set(). This must be done before any language is set (ie before any project() or enable_language() command). For example: set(CMAKE_C_COMPILER "gcc-4.2") set(CMAKE_CXX_COMPILER "/usr/bin/g++-4.2") project("YourProjectName") [edit]
默认C++11是不启用的。在src/CMakeLists.txt文件中加上这行：
SET(CMAKE_CXX_FLAGS "-std=c++11") # Add c++11 functionality
然后运行cmake ..
make VERBOSE=1
你会看到编译的g++命令后面带上了：
/usr/bin/g++-4.7 -std=c++11