c++ - 当参数按值传递时抛出异常

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Constructor with by-value parameter & noexcept

(1个答案)


去年关闭。




复制时出现类型抛出:

struct A { A(const A&) { throw 1; } };

void doit(A)
{
}

int main()
{
    A a;
    doit(a);
    return 0;
}

是在函数内部还是外部抛出异常？我可以将函数声明为noexcept吗？

最佳答案

参见C++ 17 [expr.call]/4

... The initialization and destruction of each parameter occurs within the context of the calling function. [ Example: The access of the constructor, conversion functions or destructor is checked at the point of call in the calling function. If a constructor or destructor for a function parameter throws an exception, the search for a handler starts in the scope of the calling function; in particular, if the function called has a function-try-block (Clause 18) with a handler that could handle the exception, this handler is not considered. — end example ]

因此，就像您将要说的那样，异常(exception)是“在函数外部”抛出的。您可以将其声明为 noexcept。

关于c++ - 当参数按值传递时抛出异常，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/60857182/

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Answer 1

参见C++ 17 [expr.call]/4

... The initialization and destruction of each parameter occurs within the context of the calling function. [ Example: The access of the constructor, conversion functions or destructor is checked at the point of call in the calling function. If a constructor or destructor for a function parameter throws an exception, the search for a handler starts in the scope of the calling function; in particular, if the function called has a function-try-block (Clause 18) with a handler that could handle the exception, this handler is not considered. — end example ]

因此，就像您将要说的那样，异常(exception)是“在函数外部”抛出的。您可以将其声明为 noexcept。