assert(false) in release == splinter in eye

[Christopher Bergqvist]

Thanks for the support guys. :)

Unfortunately "halt" would still need to be a keyword if one wants to keep
the full behavior of assert(0), where the compiler knows that it affects the
control-flow of the program.

Legal:
int main()
{
    assert(0);
}

Illegal (Error: function D main has no return statement, but is expected to
return a value of type int):
int main()
{
    int a = 0;
    assert(a);
}


2010/10/10 Tomek Sowiński <just at ask.me>

> Christopher Bergqvist napisał:
>
> > Hi,
> >
> > Time for some Sunday nitpicking. While reading TDPL, one thing that stuck
> > out to me was the special behavior of assert(false). Consider the
> > following program compiled with "-release".
> >
> > void main()
> > {
> >     int a = 0;
> >     assert(a);
> > }
> >
> > That program will run without errors. Changing the type of variable a
> from
> > "int" to "enum" results in the program segfaulting thanks to the compiler
> > being able to know the value of the expression "a" at compile time and
> > inserting a HLT/"halt" instruction. Having the ability to change
> something
> > subtle in a more complex expression or series of expressions without
> > realizing you made a compile time assert(false) which crashes your
> program
> > feels ugly.
> >
> > I would prefer it if assert() didn't have this special type of behavior,
> > and that a "halt" keyword or equivalent was introduced. What do you
> think?
>
> I have the same feeling. 'halt' is good, 'fail' is good too. It doesn't
> have to be a keyword, a
> function in object.d would suffice.
>
> BTW, does anybody know the reason for the assert(0) infernal syntax?
>
> --
> Tomek
>
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