require et random_device for cons token test

[Jonathan Wakely]

On 25/03/21 08:03 -0300, Alexandre Oliva wrote:
>On Mar 24, 2021, Jonathan Wakely <jwakely@redhat.com> wrote:
>
>> diff --git a/libstdc++-v3/testsuite/util/testsuite_random.h b/libstdc++-v3/testsuite/util/testsuite_random.h
>> index 0b670bfb771..c8323078492 100644
>> --- a/libstdc++-v3/testsuite/util/testsuite_random.h
>> +++ b/libstdc++-v3/testsuite/util/testsuite_random.h
>> @@ -197,6 +197,19 @@ namespace __gnu_test
>>    }
>>  #endif
>
>> +  // Check whether TOKEN can construct a std::random_device successfully.
>> +  inline bool
>> +  random_device_available(const std::string& token) noexcept
>> +  {
>> +    try {
>> +      std::random_device dev(token);
>> +      return true;
>> +    } catch (...) {
>> +      std::printf("random_device(\"%s\") not available\n", token);
>
>Another nit: I'm seeing line noise (do people still use this term? :-)
>in libstdc++.log where unavailable random_device tokens should appear.
>I suspect the token has to be converted to a C string in the call above.

Doh, the function took a const char* then I changed it to std::string
because some of the callers wanted to pass a std::string. I'll fix it
in my branch.