Re: Initialization of reference to non-const

"Bo Persson" <>
11 Jun 2006 17:37:01 -0400
"ali" <> skrev i meddelandet

Can anyone please explain to me the rational behind the decision
I cannot bind a reference to non-const to a temporary?

  void bar_01(Foo& f) {}
  Foo bar_02() { return Foo(); }

  Foo& f = bar_02();

The reason is that you can update the non-const parameter, but will
lose the updates if it is a temporary. The implicit convertions of C
types also plays tricks, and creates temporaries in unexpected places.

void inc(float& x)
{ x += 1; }

int i = 0;
float y = 0;

inc(y); // works
inc(i); // doesn't work

and what about


Both of the two last lines give me on Comeau/gcc/...

  error: initial value of reference to non-const must be an lvalue

(while, btw Vis C++ 8 happily goes along with it).

That's a compiler extension, on by default. You can disable it with

Bo Persson

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