C++ throw() 优化

Question

根据 Optimizing C++ ,

Use the empty exception specification (that is, append throw() to the declaration) for the functions you are sure will never throw exceptions.

如果我知道我的 90% 的方法不会抛出异常怎么办？将 throw() 附加到所有这些方法似乎非常规且冗长。如果没有，有什么好处？还是我误解了什么？

Answer 1

C++11 引入了 noexcept , throw有点被弃用(并且根据 this 效率较低)

noexcept is an improved version of throw(), which is deprecated in C++11. Unlike throw(), noexcept will not call std::unexpected and may or may not unwind the stack, which potentially allows the compiler to implement noexcept without the runtime overhead of throw().

当违反空抛出规范时，您的程序将终止；这意味着你应该只将你的函数声明为不抛出，只有当它们有不抛出异常保证时。

最后，您需要一个非抛出的移动构造函数(用 noexcept 指定)才能使用 std::vector<T>::push_back 的右值引用版本(参见更好的解释 here )