Re: [Boost-users] [bind] using NULL as a bound argument

On Mon, Jun 16, 2008 at 10:45 AM, Marc Horowitz wrote:

"Ovanes Markarian" writes:

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in this case template deduction does not work (or works a bit different as assumed).

This one should work: (std::tr1::bind(f, _1))(static_cast(NULL));

This works, but it is inconvenient. It is not always clear at first what the type of an argument which takes NULL is, especially if one is modifying existing code. You can compile, see what the error message says, and copy that type into the code, but I was hoping to avoid this.

This is static type safety of C++. The next standard will introduce null_ptr. If used as you suggested, then nothing prevents this BAD code to compile: (std::tr1::bind(f, _1))(1);

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NullPlaceholder works, because it makes the cast in operator() for you.

Yes, I am aware of this, which is why I wrote it that way. I was hoping to learn if someone had developed a cleaner workaround, and to get the documentation improved if not.

I don't see it as a workaround, but a clean approach to initialize pointer values with NULL-value only. This approach cleanly prevents the upper error case as well.

Marc

Regards, Ovanes