V1041. Class member is initialized with dangling reference.

This diagnostic detects cases when class members are initialized with a "bad" pointer or reference.

Consider the following example:

class Foo {
  int *x;
  int &y;
  Foo(int a, int b);
};

Foo::Foo(int a, int b) :
  x(&a),  // <=
  y(b)    // <=
{};

The 'x' variable is a pointer initialized to the address of the 'a' variable. The 'a' variable is an argument and it is local to the constructor, so its scope is narrower than that of 'x'. As a result, after execution leaves the constructor, the 'x' variable will be storing an incorrect pointer.

The same is true for the reference 'y'.

This is what the correct version looks like:

class Foo {
  int *x;
  int &y;
  Foo(int *a, int &b) :
    x(a),
    y(b)
  {}
};

Foo::Foo(int *a, int &b) :
  x(a),
  y(b),
  {}
};

Now the address and the reference are passed directly to the constructor; their scope is still limited to that of the constructor, while their values' scope is not.

This diagnostic is classified as: