[PATCH] D33895: [Support] Add TempFailureRetry helper function

[Pavel Labath via Phabricator via llvm-commits]

labath added inline comments.


================
Comment at: include/llvm/Support/Errno.h:32
 
+template <typename Fun, typename... Args>
+inline typename std::result_of<Fun && (Args && ...)>::type
----------------
EricWF wrote:
> The value-categories seem all messed up here. There is no reason to be using `&&` anywhere, since all of the arguments and the function are lvalues. Personally I would write this function as:
> 
> ```
> template <typename Fun, typename... Args,
>           typename ResultT = typename std::result_of<Fun const& (const Args&...)>::type>
> inline ResultT RetryAfterSignal(ResultT Fail, const Fun &F, const Args &... As) {
>   ResultT Res;
>   do
>     Res = F(As...);
>   while (Res == Fail && errno == EINTR);
>   return Res;
> }
> ```
Thanks, that looks much better. I'll have to remember the extra template arg trick.

Using the correct value category is still somewhat of a mystery to me.


https://reviews.llvm.org/D33895