More specialized name for the no-throw declaration of the exception::what() method. Use BSLS_EXCEPTION_VIRTUAL_NOTHROW instead.
exception::what()
BSLS_EXCEPTION_VIRTUAL_NOTHROW
Declared in <bsls_exceptionutil.h>
<bsls_exceptionutil.h>
#define BSLS_EXCEPTION_WHAT_NOTHROW