I can't find the thread where clipka pointed out to me that the leading
underscore is a reserved macro.  This has been my style since before
those punks at std were playing their daddy's Atari.

Well, the latest version of Qt turns on a shitload of warnings. One of
which is "Use of reserved macro name". baf.

Another one is sign coercion, i.e. use of unsigned int for an int.
I would be happier if Qt had added unsigned overloads, like resizing a
window, as if I could make a window -10 pixels wide.

Oh, ok...

quint32 h = 10, w = 10;
window.resize( (int)h, (int)w );

*Now* I get a warning "use of old style conversion".

Well yeah, I'm old. Shut up.  Either remove the feature or shutup. :)

-- 
dik
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Am 07.08.2018 um 04:01 schrieb dick balaska:
> I can't find the thread where clipka pointed out to me that the leading
> underscore is a reserved macro.  This has been my style since before
> those punks at std were playing their daddy's Atari.

I can repeat it if that helps ;)

In the C++11 standard, the corresponding rules can be found in section
17.6.4.3.2, "Global names".

If you don't have access to a copy of the C++11 standard, I can
recommend this website, which according to my experience sums up the
actual standard pretty faithfully and precisely (and is also very
helpful to figure out in which version of C++ a particular feature is
available):

    https://en.cppreference.com/w/cpp/language/identifiers


If it soothes your pain a bit, POV-Ray v3.7.0 also wrongfully used a few
reserved names.


> Well, the latest version of Qt turns on a shitload of warnings. One of
> which is "Use of reserved macro name". baf.

And rightfully it does: Using any reserved identifier for your own
purposes leads to "undefined behaviour" - meaning your compiled program
could do anything, even cause the Higgs field to spontaneously decay to
a lower potential and thereby wipe out the entire universe. We don't
want that to happen.

> Another one is sign coercion, i.e. use of unsigned int for an int.
> I would be happier if Qt had added unsigned overloads, like resizing a
> window, as if I could make a window -10 pixels wide.
> 
> Oh, ok...
> 
> quint32 h = 10, w = 10;
> window.resize( (int)h, (int)w );
> 
> *Now* I get a warning "use of old style conversion".

That's a more petty warning, because the program is technically well-formed.

To avoid the warning, try

    window.resize( int(h), int(w) );

which by definition does exactly the same, but is considered C++ (as
opposed to C) style. The drawback is that the type must be a single
word, e.g. `signed int(h)` won't work.

Even better, because less ambiguous (especially when casting non-trivial
types):

    window.resize( static_cast<int>(h), static_cast<int>(w) );

Of course the drawback is that it's more to type (or read, for that matter).

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