Can we forbid the usage of !! (double exclamation mark) in c++ code?

[felixf4xu]

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Hi,

When I read code like this:

      if (!!left_lanes) {
        return *left_lanes;
      }

At first glance I thought !! is a new operator introduced by newer version of c++, but then I realized it's actually NOT operator for 2 continuous times.

I would say this is not necessary.

Can we have a style guide related to it? either forbid it or encourage it?

[yukkysaito]

I don't see this expression used very often either, but it seems that using double negation allows you to check whether a pointer is valid.
The following is an explanation by ChatGPT.