C ++：抛出异常，使用'new'或不？ [英] C++: Throwing exceptions, use 'new' or not?

问题描述

使用抛出新的FoobarException（Baz参数）; 或抛出FoobarException（Baz参数）; ？

抓到时，我总是使用 catch（FoobarException& e）以防万一，但我从来没有找到一个坚实的答案是否我不得不使用新的或不在C ++（Java绝对），或者它只是程序员的偏好。

解决方案

所以这是正确的方法：

  try 
 {
 throw FoobarException（argument）; 
} 
 catch（const FoobarException& ex）
 {
 cout<< ex.what（）<< ENDL; 
} 
  

不要抛出使用new创建的异常，因为谁负责删除它没有明确定义。此外，在错误处理期间执行分配可能会引发另一个异常，从而掩盖原始问题。

您不必通过const引用（非const将正常工作） ），但我喜欢这样做。然而，你应该总是通过引用（而不是值）来捕获异常。如果没有，可以将异常类型切片。

Is it proper to use throw new FoobarException(Baz argument); or throw FoobarException(Baz argument);?

When catching I always use catch(FoobarException& e) "just in case" but I never could find a solid answer whether I had to use new or not in C++ (Java definitely) or if it was just a preference of the programmer.

解决方案

Exceptions in C++ should be thrown by value, and caught by reference.

So this is the proper way:

try
{
    throw FoobarException(argument);
}
catch( const FoobarException &ex )
{
    cout << ex.what() << endl;
}

Don't throw an exception created with new, since who's responsible for deleting it is not well-defined. In addition, performing allocations during error handling can throw another exception, obscuring the original problem.

You don't have to catch by const reference (non-const will work fine), but I like doing it anyway. You should however always by reference (not by value) to catch the exception polymorphically. If you don't, the exception's type could be sliced.

这篇关于C ++：抛出异常，使用'new'或不？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！