让我们来看看下面的代码:C函数名称或函数指针?
#include <stdio.h>
typedef int (*callback) (void *arg);
callback world = NULL;
int f(void *_) {
printf("World!");
return 0;
}
int main() {
printf("Hello, ");
// world = f;
world = &f; // both works
if (world != NULL) {
world(NULL);
}
}
当设置world
变量,既 world = f;
和world = &f;
作品。
应该使用哪一个?它依赖于编译器还是C版本?
% gcc -v
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 8.0.0 (clang-800.0.38)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
http://stackoverflow.com/questions/6293403/in-c-what-is-the-difference-between-function-and-function-when-passed-as-a – Pavel
http:// stackoverflow .COM /问题/ 3674200 /什么,做-A-的typedef与 - 括号样的typedef INT-fvoid均值 - 是 - 它-A –