tint: Fix vector equality operator

Change-Id: Ic8e66016beb8fd6a3046beaccbb9c07acbd765d5
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/105260
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Auto-Submit: Ben Clayton <bclayton@google.com>

src/tint/utils/vector.h

@@ -463,15 +463,17 @@ class Vector {
     /// Equality operator
     /// @param other the other vector
     /// @returns true if this vector is the same length as `other`, and all elements are equal.
-    bool operator==(const Vector& other) const {
+    template <typename T2, size_t N2>
+    bool operator==(const Vector<T2, N2>& other) const {
         const size_t len = Length();
-        if (len == other.Length()) {
+        if (len != other.Length()) {
+            return false;
+        }
         for (size_t i = 0; i < len; i++) {
             if ((*this)[i] != other[i]) {
                 return false;
             }
         }
-        }
         return true;
     }
 
@@ -479,7 +481,10 @@ class Vector {
     /// @param other the other vector
     /// @returns true if this vector is not the same length as `other`, or all elements are not
     ///          equal.
-    bool operator!=(const Vector& other) const { return !(*this == other); }
+    template <typename T2, size_t N2>
+    bool operator!=(const Vector<T2, N2>& other) const {
+        return !(*this == other);
+    }
 
   private:
     /// Friend class (differing specializations of this class)

src/tint/utils/vector_test.cc

@@ -2060,6 +2060,15 @@ TEST(TintVectorRefTest, ConstBeginEnd) {
     EXPECT_EQ(vec_ref.end(), &vec[0] + 3);
 }
 
+TEST(TintVectorTest, Equality) {
+    EXPECT_EQ((Vector<int, 2>{1, 2}), (Vector<int, 2>{1, 2}));
+    EXPECT_EQ((Vector<int, 1>{1, 2}), (Vector<int, 3>{1, 2}));
+    EXPECT_NE((Vector{1, 2}), (Vector{1}));
+    EXPECT_NE((Vector{1}), (Vector{1, 2}));
+    EXPECT_NE((Vector{1, 2}), (Vector{2, 1}));
+    EXPECT_NE((Vector{2, 1}), (Vector{1, 2}));
+}
+
 }  // namespace
 }  // namespace tint::utils