Suppose I define a function in C++ as follows:
void foo(int &x) const {
x = x+10;
}
And suppose I call it as follows:
int x = 5;
foo(x);
Now typically (without the const
keyword), this would successfully change the value of x
from the caller's perspective since the variable is passed by reference. Does the const
keyword change this? (ie From the caller's perspective, is the value of x
now 15?)
I guess I'm confused as to what the const
keyword does when it is appended to the end of a function definition... any help is appreciated.
This won't work. You can only const-qualify a member function , not an ordinary nonmember function.
For a member function, it means that the implicit this
parameter is const-qualified, so you can't call any non-const-qualified member functions or modify any non-mutable data members of the class instance on which the member function was called.
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