Visual C++不支持set_unexpected

今天看Thinking in C++ 2nd v2第一章的关于set_unexpected, 测试书里的代码, 发现和书上的结果不同, 代码如下:

//: C01:BadException.cpp {-bor}

#include <exception>    // For std::bad_exception

#include <iostream>

#include <cstdio>

using namespace std;

// Exception classes:

class A {};

class B {};

// terminate() handler

void my_thandler() {

  cout << "terminate called" << endl;

  exit(0);

}

// unexpected() handlers

void my_uhandler1() { throw A(); }

void my_uhandler2() { throw; }

// If we embed this throw statement in f or g,

// the compiler detects the violation and reports

// an error, so we put it in its own function.

void t() { throw B(); }

void f() throw(A) { t(); }

void g() throw(A, bad_exception) { t(); }

int main() {

  set_terminate(my_thandler);

  set_unexpected(my_uhandler1);

try {

    f();

  } catch(A&) {

    cout << "caught an A from f" << endl;

  }

  set_unexpected(my_uhandler2);

try {

    g();

  } catch(bad_exception&) {

    cout << "caught a bad_exception from g" << endl;

  }

try {

    f();

  } catch(...) {

    cout << "This will never print" << endl;

  }

} ///:~

 

书上说结果将会调用自定义的异常handler:

caught an A from f

caught a bad_exception from g

terminate called

可我用Visual C++运行的结果是:

terminate called

立刻跑到Google搜索, 结果搜到MSDN关于set_unexpected的页面:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore98/html/_crt_set_unexpected.asp

MSDN最后说:

In the current Microsoft implementation of C++ exception handling, unexpected calls terminate by default and is never called by the exception-handling run-time library. There is no particular advantage to calling unexpected rather than terminate.

噢, 微软就是牛哈, 说不支持就是不支持~ 不过感觉微软做的也对, 这些东东用多了代码就会变的很乱了.  像这种问题还是应该使用良好的设计来避免~