Re: [C++ RFC / Patch] Implementing "Deducing "noexcept" for destructors"

[Jason Merrill <jason at redhat dot com>]

On 03/28/2012 11:02 AM, Paolo Carlini wrote:
> +&&  !comp_except_specs (new_exceptions, old_exceptions, ce_normal)
> +      /* Special case in C++11: noexcept has been deduced as true for
> +	 the declaration and there is no exception-specification on the
> +	 definition.  */
> +&&  !(DECL_DESTRUCTOR_P (new_decl)
> +	&&  cxx_dialect>= cxx0x
> +	&&  !new_exceptions&&  TYPE_NOEXCEPT_P (old_type)))

TYPE_NOEXCEPT_P is the wrong test; the implicit declaration might have 
an exception-specification that allows some or all exceptions.  I think 
the most straightforward thing would be to add the implicit 
exception-specification immediately when declaring a destructor outside 
the class, so that by the time we get to 
check_redeclaration_exception_specification the EH specs will match.

Jason