[PATCH] D124690: [clangd] add inlay hints for std::forward-ed parameter packs

[Tobias Ribizel via Phabricator via cfe-commits]

upsj added inline comments.


================
Comment at: clang-tools-extra/clangd/AST.cpp:682
+      if (const auto *TTPD =
+              dyn_cast<TemplateTypeParmDecl>(TemplateParams.back())) {
+        const auto *TTPT =
----------------
nridge wrote:
> upsj wrote:
> > nridge wrote:
> > > I don't think there is any requirement that a pack be a trailing **template** parameter. For example, the following is valid:
> > > 
> > > ```
> > > template <typename... B, typename A>
> > > void foo(A, B...);
> > > 
> > > void bar() {
> > >   foo(1, 2, 3);
> > > }
> > > ```
> > Do you have a suggestion for how to find this pack in general? I would like to keep this function as efficient as possible, since it's used everywhere
> > Do you have a suggestion for how to find this pack in general?
> 
> Just iterate backwards through `TemplateParams` rather than only considering `TemplateParams.back()`, I suppose.
> 
> > I would like to keep this function as efficient as possible, since it's used everywhere
> 
> The `ParmVarDecl*` overload of `getPackTemplateParameter()` is called a lot via the `IsExpandedPack` lambdas, but this overload is only called once per depth level.
Ah thanks, of course! I got tricked by my own overloads.


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  https://reviews.llvm.org/D124690/new/

https://reviews.llvm.org/D124690