c++ - 源码安装了gcc-5.4.0，为什么找不到unordered_map.h等头文件？

Question

公司的linux服务器是基于redhat修改的，原来安装了gcc-4.4.4，由于对c++11支持不好，因此想升级gcc。由于该机器是同事公用的，所以不想影响其他同时，在自己的目录下用gcc-5.4.0的源码进行安装。安装完成之后gcc-5.4.0下有如下几个目录：

1. bin　　　　　　　有gcc g++ c++等二进制文件，g++ -v输出版本确实为5.4.0

2. include　　　　　没有任何文件，经查询，发现老版本的gcc在/usr/include/c++/4.4.4/目录下能找到stl头文件

3. lib　　　　　　　一些库文件

4. lib64　　　　　　一些库文件

5. libexec　　　　　一些库文件

6. share　　　　　　其他信息

google了半天也都是说什么没加-std=c++11等等，我加上去了也不行。请大神们看看！感谢！

Answer 1

The header file of

c++ is in a folder called c++, search for it~~
However, there is no unordered_map.h file, there is unordered_map, and the header file of c++ is
without extension. If you really want to find unordered_map.h, it may be under the bits folder, but the name is not definitely this. It depends on how the compiler names it

Answer 2

Have you used find? You can try locate unordered_map.h

Answer 3

Is it just compiled without executing make install? Those header files should be copied during installation. You can install it in your own directory, but it is best to install it under /usr/local, which will not interfere with the system. And because of this, the gcc installed from the source code has a default search path of /usr/local/include.
Check whether you wrote the correct prefix during configure?