An upcoming change in mainline clang will be validating templated code even when the specific path is not taken during compilation.

dgovil · dgovil · commit 84f9d555b618 · 2024-12-02T17:01:23.000-08:00
This fix removes on such unused path from SdfChildrenProxy in the assignment operator where there is no implementation of _Set
diff --git a/pxr/usd/sdf/childrenProxy.h b/pxr/usd/sdf/childrenProxy.h
@@ -52,13 +52,6 @@ class SdfChildrenProxy {
             return *_pos;
         }
 
-        template <class U>
-        _ValueProxy& operator=(const U& x)
-        {
-            _owner->_Set(*_pos, x);
-            return *this;
-        }
-
         bool operator==(const mapped_type& other) const
         {
             return *_pos == other;

Original file line number	Diff line number	Diff line change
`@@ -52,13 +52,6 @@ class SdfChildrenProxy {`
`52`	`52`	`return *_pos;`
`53`	`53`	`}`
`54`	`54`
`55`		`- template <class U>`
`56`		`- _ValueProxy& operator=(const U& x)`
`57`		`- {`
`58`		`- _owner->_Set(*_pos, x);`
`59`		`- return *this;`
`60`		`- }`
`61`		`-`
`62`	`55`	`bool operator==(const mapped_type& other) const`
`63`	`56`	`{`
`64`	`57`	`return *_pos == other;`