Accessing a dangling reference
suggest changeIt is illegal to access a reference to an object that has gone out of scope or been otherwise destroyed. Such a reference is said to be dangling since it no longer refers to a valid object.
#include <iostream>
int& getX() {
int x = 42;
return x;
}
int main() {
int& r = getX();
std::cout << r << "\n";
}
In this example, the local variable x
goes out of scope when getX
returns. (Note that lifetime extension cannot extend the lifetime of a local variable past the scope of the block in which it is defined.) Therefore r
is a dangling reference. This program has undefined behavior, although it may appear to work and print 42
in some cases.
Found a mistake? Have a question or improvement idea?
Let me know.
Table Of Contents