C++的常引用

標籤：

Reference to const

We can bind a reference to const to a nonconst object, a literal, or a more general expression:

    int i = 42;const int &r1 = i;//bind a const int& to a plain int objectconst int &r2 = 42;//ok.r1 is a reference to constconst int &r3 = r1 * 2;         //ok.r3 is a reference to constint &r4 = i * 1;//error.r4 is a plain,nonconst reference

    double dval= 30;const int &rDval = dval; dval = 42;cout << rDval << endl; // print 30

The compiler transforms this code into something like:

    const int temp = dval;const int &rDval = temp;

In this case, rDval is bound to a temportary object.

C++的常引用