c++ - 接受右值引用参数的模板函数

Question

#include <iostream>
#include <type_traits>
template<typename T>void g(T&& val);
int main() 
{
    int i = 0;
    const int ci = i;
    g(i*ci);//请问这里模板实例化的T是int还是int&&？我认为是int，但很多地方说是int&&，感觉不可思议
}

Answer 1

If I remember correctly, T is int and val is int&&. You can read the first chapter of effective modern c++

Answer 2

Write a program to verify it

Sorry, I just wrote it wrong. The following is the correct verification scheme.

The output is 10 and 999
I just want to output val in g(), the value is 10
Then I modify the val in g(), and then return When main outputs 999
, it means that the parameters here are passed by reference, not by value.
In other words, the message is T&

Answer 3

The answer is: non-const rvalue reference.
This problem is about understanding the left and right values.