[PATCH] D135404: [clang-tidy] Add a checker for converting into C++17 variable template type traits

[Nathan James via Phabricator via cfe-commits]

njames93 added a comment.

I'd also suggest using the `IgnoreUnlessSpelledInSource` traversal kind here. Given that most of the time these will be instantiated we don't want to warn and emit a fix for each instantiation, Or you could just add `unless(isInTemplateInstantiation())` to your matcher.



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Comment at: clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp:86
+    auto CurrentText = tooling::fixit::getText(*MatchedDecl, *Result.Context);
+    if (replacement_regex.match(CurrentText))
+      IssuedDiag << FixItHint::CreateReplacement(
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royjacobson wrote:
> njames93 wrote:
> > This fixit logic looks cumbersome, just replace the qualifier loc(::)to the declared with an `_v`. But only iff the qualified name loc is not a macro.
> I think to do that I have to get the location of the template-id of the qualifier from the ClassTemplateSpecializationDecl, but I haven't really managed to do that. Or is there maybe a way to get the lexer tokens list of a source range or something like that?
Take a look here https://godbolt.org/z/Wj5bjbqGh
You'd want to create an insertion of `_v` at the start of the `<`
`getQualifierLoc().getTypeLoc().getAs<clang::TemplateSpecializationTypeLoc>().getLAngleLoc()`
Then a removal from the start of the `::` until the end of the whole expr
`{getQualifierLoc().getEndLoc(), getEndLoc()}`


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Comment at: clang-tools-extra/docs/clang-tidy/checks/modernize/type-traits.rst:34
+    same name and a ``_v`` suffix.
\ No newline at end of file

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https://reviews.llvm.org/D135404