Re: [PATCH 2/2] PR debug/63240 Add DWARF representation for C++11 defaulted member function.

[Jason Merrill <jason at redhat dot com>]

On 10/03/2014 10:35 AM, Mark Wielaard wrote:
> Say you have a user defined copy constructor. The DWARF consumer will
> see the declaration and can assume the class won't have a default
> constructor (unless that one is explicitly declared too). But currently
> the DWARF consumer cannot know whether that move constructor was really
> a user defined. If it was declared with = default; then it will see the
> move constructor and erroneously conclude that it was user defined and
> so the class won't have a default constructor generated for it.

That's not erroneous, a declaration with =default still suppresses the 
default constructor.  "If there is no user-declared constructor for 
class X, a constructor having no parameters is implicitly declared as 
defaulted."

"user-declared" includes declarations that are defaulted in the class 
body.  "user-provided" is the category that does not include such 
declarations.

Jason