GCC 4.4.6 const char* to char* compiler error

今天在编译一个同事的代码发现一个小问题，就是报编译错误： error: invalid conversion from ‘const char*’ to ‘char*’，报错出在strstr这个函数，但是他原来编译又是ok的。猜测是GCC版本不一致导致的问题，一看果然是，他用的gcc 4.1.2，我用的gcc 4.4.6。但是为啥gcc 4.4.6编译会报错呢，查了一下gcc 手册：

Strict null-terminated sequence utilities

Some of the standard C++ library include files have been edited to use replacement overloads for some common C library functions (if available), with the goal of improving const-correctness: functions passed a const char* return const char*.
The table below shows the functions and files that have been changed.

Header	Functions
<cstring>	strchr, strpbrk, strrchr, strstr, memchr
<cwchar>	wcschr wcspbrk, wcsrchr, wcsstr, wmemchr

An example.

#include <cstring>

const char* str1;
char* str2 = strchr(str1, 'a');

Gives the following compiler error:

error: invalid conversion from ‘const char*’ to ‘char*’

Fixing this is easy, as demonstrated below.

#include <cstring>

const char* str1;
const char* str2 = strchr(str1, 'a');

More information about the C++ standard requirements can be found in chapter 21, section "Null-terminated sequence utilities."

链接：https://gcc.gnu.org/gcc-4.4/porting_to.html
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原来是C++的标准库头文件有变化，目标是“improving const-correctness”，其中就有strstr这个函数。好吧，在原来的代码修改了加了强制转化就ok了。