Sorry it wasn't the best example. Suppose you have:

#include <string>


namespace personal

{

struct string : std::wstring

{

     typedef std::wstring base;

[...]


     char const * encoded_c_str(std::string && r = std::string())
     {
         r = std::string(base::begin(), base::end());

         return r.c_str();
     }
};

}

personal::string s = "Hello world";

cout << s.encoded_c_str() << endl; // will be just fine


Regards,

-- 
*Phil Bouchard*
Founder & CTO
C.: (819) 328-4743
Fornux Logo <http://www.fornux.com>
On 3/28/21 5:00 PM, Phil Bouchard via Std-Proposals wrote:
>
> Around 20 years ago the GCC compiler had what was called "named return 
> values". It got taken away because compiler optimizations could 
> generate equivalent code.
>
> But I just found one case where this can't be true and I wanted to 
> share my workaround with the community for potential discussion. 
> Suppose you have a std::wstring wrapper:
>
> #include <string>
>
>
> namespace personal
>
> {
>
> struct string : std::wstring
>
> {
>
>     typedef std::string base;
>
> [...]
>
>
>     wchar_t const * get(std::wstring && r = std::wstring())
>     {
>         r = std::wstring(base::begin(), base::end());
>
>         return r.c_str();
>     }
> };
>
> }
>
> personal::string s = "Hello world";
>
> cout << s.get() << endl; // will be just fine
>
>
> In the aforementioned case, I am creating the return value before the 
> function get() is called; this way the returned c_str() will live 
> during the duration of the temporary variable created thus will not 
> get destroyed within the function.
>
> Anyway I just thought this might be useful to know.
>
>
> Regards,
>
> -- 
>
> *Phil Bouchard*
> Founder & CTO
> C.: (819) 328-4743
>
> Fornux Logo <http://www.fornux.com>
>