Or you evaluate a non-constexpr expression inside the assert (there is a
pointer derefencing happening there that could be the culprit if it points
to something not constant evaluat-able).

// Robin

On Wed, Mar 26, 2025, 15:52 Jonathan Wakely via Std-Proposals <
std-proposals_at_[hidden]> wrote:

>
>
> On Wed, 26 Mar 2025 at 14:40, Frederick Virchanza Gotham via Std-Proposals
> <std-proposals_at_[hidden]> wrote:
>
>> Today my compiler gave me the following output:
>>
>> md5.hpp:244:21: error: call to non-‘constexpr’ function ‘void
>> __assert_fail(const char*, const char*, unsigned int, const char*)’
>> 244 | assert( 0u == (*ptr >> 8u) );
>>
>>
>> We should be able to use 'assert' in a constexpr function.
>
>
> You can.
>
>
>> If the
>> function is invoked at compile time (instead of runtime), then it
>> should be as if the 'assert' was never there. This would be the
>> easiest way of doing it.
>>
>
> I don't see why we'd want that.
>
>
>>
>> A more complicated way of doing it would be to get the compiler at
>> compile time to actually evaluate the assertion, and to cease
>> compiling if the assertion fails -- this would be ideal.
>>
>
> Isn't that exactly what happened in this case?
>
> assert is already allowed in constexpr functions, there's only a problem
> if the assertion fails. If that happens, it tries to call a non-constexpr
> function and you get an error.
>
>
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>