如何在编译时测试当前版本的GCC? [英] How to test the current version of GCC at compile time?
本文介绍了如何在编译时测试当前版本的GCC?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想根据GCC的版本添加其他文件.更准确地说,我想写:
I would like to include a different file depending on the version of GCC. More precisely I want to write:
#if GCC_VERSION >= 4.2
# include <unordered_map>
# define EXT std
#elif GCC_VERSION >= 4
# include <tr1/unordered_map>
# define EXT std
#else
# include <ext/hash_map>
# define unordered_map __gnu_cxx::hash_map
# define EXT __gnu_cxx
#endif
我不在乎3.2之前的gcc.
I don't care about gcc before 3.2.
我很确定在预处理时为此定义了一个变量,只是找不到了.
I am pretty sure there is a variable defined at preprocessing time for that, I just can't find it again.
推荐答案
好吧,在进行更多搜索之后,一种可行的方法是使用features.h
中定义的__GNUC_PREREQ
.
Ok, after more searches, it one possible way of doing it is using __GNUC_PREREQ
defined in features.h
.
#ifdef __GNUC__
# include <features.h>
# if __GNUC_PREREQ(4,0)
// If gcc_version >= 4.0
# elif __GNUC_PREREQ(3,2)
// If gcc_version >= 3.2
# else
// Else
# endif
#else
// If not gcc
#endif
这篇关于如何在编译时测试当前版本的GCC?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文