For objects of class type, copy-initialization can be used only when specifying a single argument or when we explicitly build a temporary object to copy.

对于类的对象，当指定单一的实参或者为了拷贝明确构建临时对象时，才能使用拷贝初始化。

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For objects of class type, copy-initialization can be used only when specifying a single argument or when we explicitly build a temporary object to copy.

对于类的对象，当指定单一的实参或者为了拷贝明确构建临时对象时，才能使用拷贝初始化。

youdao