pop_back() 返回值?
为什么 pop_back()
没有返回值?我在谷歌上搜索过这个,发现它更有效.这是在标准中这样做的唯一原因吗?
Why doesn't pop_back()
have a return value? I have Googled regarding this and found out that it makes it more efficient. Is this the only reason for making it so in the standard?
推荐答案
我认为复制最后一个对象的实例可能会引发异常这一事实与此有关.这样做时,您将丢失对象,因为 pop_back() 确实将其从容器中删除.用几行代码更好:
I think there is something related to the fact that copying an instance of the last object could throw an exception. When doing so, you're losing your object, since pop_back() did remove it from your container. Better with a few lines of code:
std::vector<AnyClass> holds = {...} ;
try {
const AnyClass result = holds.pop_back(); // The copy Ctor throw here!
} catch (...)
{
// Last value lost here.
}
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