Re: strange operator method

From:
Victor Bazarov <v.bazarov@comcast.invalid>
Newsgroups:
comp.lang.c++
Date:
Wed, 30 Nov 2011 16:32:37 -0500
Message-ID:
<jb67dl$sej$1@dont-email.me>
On 11/30/2011 3:53 PM, Christopher wrote:

On Nov 30, 1:46 pm, bartek szurgot<b...@no.spam> wrote:

it is a conversion operator. consider following code:

struct X
{
   //operator int(void) { return 42; }

};

int main(void)
{
   X x;
   int i=x;
   return i;

}

it won't compile, until you uncomment operator for automatic X->int
conversion. then return value of the program will be 42, as expected.


If a "conversion" operator is supplied for a class or struct, is its
usage umm... always valid and implicit?


Not sure what you mean by "valid" here.

i.e Can I pass x to a function that expects an int?


Yes.

     Can I stream it into a ostringstream?
     etc.?


You can try.

The point is that by adding a conversion operator you allowing an
implicit conversion from that type to the return type of that operator.
  Whether it's going to be used depends on the context.

V
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