[ADT] Fix missing 'template' keyword

[sdkrystian]

Fixes instances where the template keyword should be used to interpret < as the delimiter of a template-argument-list after #92957.

[llvmbot]

@llvm/pr-subscribers-llvm-adt

Author: Krystian Stasiowski (sdkrystian)

Changes

Fixes instances where the template keyword should be used to interpret < as the delimiter of a template-argument-list after #92957.

---

Full diff: https://github.com/llvm/llvm-project/pull/98252.diff

1 Files Affected:

• (modified) llvm/include/llvm/ADT/ArrayRef.h (+2-2)

diff --git a/llvm/include/llvm/ADT/ArrayRef.h b/llvm/include/llvm/ADT/ArrayRef.h
index ac40ec4a6b240..18fff7808ace1 100644
--- a/llvm/include/llvm/ADT/ArrayRef.h
+++ b/llvm/include/llvm/ADT/ArrayRef.h
@@ -460,8 +460,8 @@ namespace llvm {
 
     OwningArrayRef &operator=(OwningArrayRef &&Other) {
       delete[] this->data();
-      this->MutableArrayRef<T>::operator=(Other);
-      Other.MutableArrayRef<T>::operator=(MutableArrayRef<T>());
+      this->template MutableArrayRef<T>::operator=(Other);
+      Other.template MutableArrayRef<T>::operator=(MutableArrayRef<T>());
       return *this;
     }
 

[chapuni]

This fails with Ubuntu-20.04 g++.

llvm/include/llvm/ADT/ArrayRef.h:463:40: error: expected ‘;’ before ‘::’ token
  463 |       this->template MutableArrayRef<T>::operator=(Other);
      |                                        ^~
      |                                        ;
llvm/include/llvm/ADT/ArrayRef.h:464:40: error: expected ‘;’ before ‘::’ token
  464 |       Other.template MutableArrayRef<T>::operator=(MutableArrayRef<T>());
      |                                        ^~
      |                                        ;

[chapuni]

g++ (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0

[sdkrystian]

This appears to be a GCC bug. Requesting guidance from @AaronBallman @erichkeane @zygoloid.

[chapuni]

Could we revert for now?

[sdkrystian]

@chapuni I dont think this is something that can be fixed in clang. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94799

[chapuni]

So, we should revert #92957 for now, unless excluding problematic host compilers would be agreed.