To follow up on what Ian said, to make the code correct, you simply
need to change the function to take a const reference like this:

void f(const A &rA) { ... }

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Given the following snipplet:

  class A
  {
  };
  class B : public A
  {
      public:
          B(int iVal) {}
  };

  void f(A &rA) { ... }

Following the standard, is it allowed to do the following call?

  f(B(10));

I thought it were, but my compiler (MS VC++ 2008) keeps saying that it uses
a nonstandard extension for the conversion from "B" to "A&" (remark: I'm
about to switch to warning level 4).

- Marco

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On 05/ 4/10 07:07 AM, Marco Nef wrote:
> Given the following snipplet:
>
> class A
> {
> };
> class B : public A
> {
> public:
> B(int iVal) {}
> };
>
> void f(A &rA) { ... }
>
> Following the standard, is it allowed to do the following call?
>
> f(B(10));
>
> I thought it were, but my compiler (MS VC++ 2008) keeps saying that it uses
> a nonstandard extension for the conversion from "B" to "A&" (remark: I'm
> about to switch to warning level 4).

It isn't following the standard.  You are initialising a non-const
reference with a temporary.

--
Ian Collins

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