blocks|key|1527124|text|它是有效的，但如果我是你，我不会这么做。完成后，您似乎没有删除该堆数据，这意味着您已经创建了一个内存泄漏。C%2B%2B编译器负责确保异常数据在堆栈弹出时保持活动状态，因此不需要使用堆。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1527125|顺便说一句，抛出std::string不是最好的开始方法。如果使用简单的包装器对象，将来会有更大的灵活性。它现在可能只封装了一个string，但也许将来你会想要包含其他信息，比如一些导致异常的数据，或者可能是一个行号(非常常见)。您不希望在代码库中的每个位置都更改所有的异常处理，所以现在就走正道，不要抛出原始对象。|offset|length|style|CODE|1527126|entityMap^0|0|8|B|1S|6|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]|$D|N|E|O|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|P|8|@]|9|@]|A|$]]]|I|$]]

It works, but I wouldn't do it if I were you. You don't seem to be deleting that heap data when you're done, which means that you've created a memory leak. The C++ compiler takes care of ensuring that exception data is kept alive even as the stack is popped, so don't feel that you need to use the heap.

Incidentally, throwing a <code>std::string</code> isn't the best approach to begin with. You'll have a lot more flexibility down the road if you use a simple wrapper object. It may just encapsulate a <code>string</code> for now, but maybe in future you will want to include other information, like some data which caused the exception or maybe a line number (very common, that). You don't want to change all of your exception handling in every spot in your code-base, so take the high road now and don't throw raw objects.

blocks|key|1527180|text|所有这些工作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1527181|#include+<iostream>
using+namespace+std;

//Good,+because+manual+memory+management+isn't+needed+and+this+uses
//less+heap+memory+(or+no+heap+memory)+so+this+is+safer+if
//used+in+a+low+memory+situation
void+f()+{+throw+string("foo");+}

//Valid,+but+avoid+manual+memory+management+if+there's+no+reason+to+use+it
void+g()+{+throw+new+string("foo");+}

//Best.++Just+a+pointer+to+a+string+literal,+so+no+allocation+is+needed,
//saving+on+cleanup,+and+removing+a+chance+for+an+allocation+to+fail.
void+h()+{+throw+"foo";+}

int+main()+{
++try+{+f();+}+catch+(string+s)+{+cout+<<+s+<<+endl;+}
++try+{+g();+}+catch+(string*+s)+{+cout+<<+*s+<<+endl;+delete+s;+}
++try+{+h();+}+catch+(const+char*+s)+{+cout+<<+s+<<+endl;+}
++return+0;
}|code-block|syntax|javascript|1527182|您应该更喜欢h而不是f而不是g。请注意，在最不可取的选项中，需要显式释放内存。|1527183|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

All these work:

<pre><code>#include &lt;iostream&gt;
using namespace std;

//Good, because manual memory management isn't needed and this uses
//less heap memory (or no heap memory) so this is safer if
//used in a low memory situation
void f() { throw string("foo"); }

//Valid, but avoid manual memory management if there's no reason to use it
void g() { throw new string("foo"); }

//Best. Just a pointer to a string literal, so no allocation is needed,
//saving on cleanup, and removing a chance for an allocation to fail.
void h() { throw "foo"; }

int main() {
 try { f(); } catch (string s) { cout &lt;&lt; s &lt;&lt; endl; }
 try { g(); } catch (string* s) { cout &lt;&lt; *s &lt;&lt; endl; delete s; }
 try { h(); } catch (const char* s) { cout &lt;&lt; s &lt;&lt; endl; }
 return 0;
}
</code></pre>

You should prefer h to f to g. Note that in the least preferable option you need to free the memory explicitly.

blocks|key|1742268|text|是。std::exception是C%2B%2B标准库中的基本异常类。您可能希望避免将字符串用作异常类，因为它们本身会在使用过程中引发异常。如果发生这种情况，你会在哪里？|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1742269|boost在异常和错误处理的良好风格上有一个很好的document。这本书值得一读。|1742270|entityMap|0|LINK|mutability|MUTABLE|url|http://en.cppreference.com/w/cpp/error/exception|1|http://www.boost.org/community/error_handling.html^0|2|E|2|E|0|0|P|8|1|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@$9|U|A|V|1|W]]|E|$]]|$1|F|3|G|5|6|7|X|8|@]|D|@$9|Y|A|Z|1|10]]|E|$]]|$1|H|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]|P|$5|K|L|M|E|$N|Q]]]]

Yes. <a href="http://en.cppreference.com/w/cpp/error/exception" rel="noreferrer"><code>std::exception</code></a> is the base exception class in the C++ standard library. You may want to avoid using strings as exception classes because they themselves can throw an exception during use. If that happens, then where will you be?

boost has an excellent <a href="http://www.boost.org/community/error_handling.html" rel="noreferrer">document</a> on good style for exceptions and error handling. It's worth a read.

I would like to throw an exception when my C++ methods encounter something weird and can't recover. Is it OK to throw a <code>std::string</code> pointer?

Here's what I was looking forward to doing:

<pre><code>void Foo::Bar() {
 if(!QueryPerformanceTimer(&amp;m_baz)) {
 throw new std::string("it's the end of the world!");
 }
}

void Foo::Caller() {
 try {
 this-&gt;Bar(); // should throw
 }
 catch(std::string *caught) { // not quite sure the syntax is OK here...
 std::cout &lt;&lt; "Got " &lt;&lt; caught &lt;&lt; std::endl;
 }
}
</code></pre>

c++ exception : throwing std::string

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当我的C++方法遇到一些奇怪的东西并且不能恢复时，我想抛出一个异常。可以抛出一个std::string指针吗？这是我期待做的事情：void Foo::Bar() {    if(!QueryPerformanceTimer(&m_baz)) {        throw new std::string("it's th...

问c++异常:抛出std::string
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