panic!
panic!
宏可用于产生一个 panic (恐慌),并开始展开它的栈。在展开栈的同时,运行时将会释放该线程所拥有的所有资源,是通过调用对象的析构函数完成。
因为我们正在处理的程序只有一个线程,panic!
将会引发程序上报 panic 消息并退出。
// 再次实现整型的除法(/) fn division(dividend: i32, divisor: i32) -> i32 { if divisor == 0 { // 除以一个 0 时会引发一个 panic panic!("division by zero"); } else { dividend / divisor } } // `main` 任务 fn main() { // 堆分配的整数 let _x = Box::new(0i32); // 此操作将会引发一个任务失败 division(3, 0); println!("This point won't be reached!"); // `_x` 在此处将被销毁 }
由分析知道, panic!不会泄露内存
$ rustc panic.rs && valgrind ./panic
==4401== Memcheck, a memory error detector
==4401== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==4401== Using Valgrind-3.10.0.SVN and LibVEX; rerun with -h for copyright info
==4401== Command: ./panic
==4401==
thread '<main>' panicked at 'division by zero', panic.rs:5
==4401==
==4401== HEAP SUMMARY:
==4401== in use at exit: 0 bytes in 0 blocks
==4401== total heap usage: 18 allocs, 18 frees, 1,648 bytes allocated
==4401==
==4401== All heap blocks were freed -- no leaks are possible
==4401==
==4401== For counts of detected and suppressed errors, rerun with: -v
==4401== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)