Re: C++17 and "Alice in Wonderland"

From: Bo Persson (bo_at_[hidden])
Date: 2021-03-24 14:09:00

On 2021-03-24 at 14:46, Edward Diener via Boost wrote:
> On 3/24/2021 12:42 AM, Felipe Magno de Almeida via Boost wrote:
>> On Tue, Mar 23, 2021 at 5:13 PM Edward Diener via Boost
>> <boost_at_[hidden]> wrote:
>>
>> Hello Edward,
>>
>>> I apologize for this non-Boost related post, but I ran into what I
>>> thought was a C++17 bug in clang ( also in vc++14.2 C++17 ), whose
>>> explanation to me of why it is not a bug really sounds like the
>>> non-logic of "Alice in Wonderland".
>>
>> [snip]
>>
>>> My bug
>>> report is at https://bugs.llvm.org/show_bug.cgi?id=49684 and the
>>> explanation given there just eludes me as to what C++17 is doing,
>>
>> [snip]
>>
>> Aren't consts ignored in function parameters?
> 
> Why are consts ignored in function parameters ? Is not
> void f(int const) different from void f(int) ? In one the argument 
> passed can not be changed and in the other it can. How can they be the 
> same ?
> 

As a caller of the function, you cannot tell the difference.

So why should they be different?  :-)