[PATCH] D78655: [CUDA][HIP] Let non-caputuring lambda be host device

[Paul Fultz II via Phabricator via cfe-commits]

pfultz2 added a comment.

> Now, back to the specifics of your example. I'm still not 100% sure I understand what the problem is. Can you boil down the use case to an example on godbolt?

I dont have a specific example, but there could be code like this generic `clip` operator:

  template<class F, class T>
  void clip(F f,
            const T& min_val,
            const T& max_val)
  {
  
      f([=](auto x) {
          return ::min<decltype(x)>(::max<decltype(x)>(min_val, x), max_val);
      });
  }

Its not clear to the writer of the generic function that it needs to declare the lambda with an explicit HD.

> If Sam decides to incorporate support for capturing lambdas in this patch, we could still do it by restricting the capturing lambda promotion to the ones within a function scope only. I.e. lambdas created in global scope would still be host.

I think that would be acceptable. I dont think global scope capturing lambdas are very common due to possible ODR issues.


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  https://reviews.llvm.org/D78655/new/

https://reviews.llvm.org/D78655