On Mon, 7 Oct 2024 at 16:28, David Brown via Gcc-help <gcc-help@xxxxxxxxxxx>
wrote:
> On 07/10/2024 16:24, R. Diez via Gcc-help wrote:
> > Hi all:
> >
> > Sometimes, I forget to remove useless 'const' modifiers in function
> > declarations. A simplified example is:
> >
> > file.h:
> >
> > int f ( const int a ); // 'const' is useless here.
> >
> >
> > file.cpp:
> >
> > int f ( const int a )
> > {
> > return a;
> > }
> >
> >
> > Is there a way to make GCC issue warnings about those useless 'const'
> > modifiers? At the very least, it would save some head scratching during
> > code reviews.
> >
> > Apparently, clang-tidy has option
> > 'readability-avoid-const-params-in-decls' for such a warning:
> >
> >
> https://clang.llvm.org/extra/clang-tidy/checks/readability/avoid-const-params-in-decls.html
> >
> > Thanks in advance,
> > rdiez
> >
>
> You might not /want/ the "const" there, but it is not useless. It means
> you are not allowed to change the value of the parameter inside the
> function.
I think the question is about the 'const' in the non-defining declaration
of the function, i.e. "the prototype" in C terminology. It's meaningful on
the function definition, but adding or removing it on the decl in the
header makes no difference to anything.
> Some people see that as a useful thing, because they see
> modification of parameter values as unexpected and potentially confusing
> or easily misread. But if you didn't mean to have it there, then it
> becomes clutter that distracts from the code.
>
> I am curious as to why you would need to remove such a qualifier,
> however - if you don't like it, why was it there in the first place?
>
> (In general, clang-tidy has more stylistic checks than gcc or the clang
> compiler. It is quite reasonable to run clang-tidy in addition to your
> compiler, as a linter and style checker.)
>
>
