Fix use of variadic generics with [Differentiable]. (#8736)

There was a bug that causes the compiler failing to treat a `no_diff
TypePack` as a type pack, and thus diagnose an error when resolving the
following call.

The fix is to unwrap any ModifiedType wrappers in `IsTypePack()` check.

1 files changed, 3 insertions, 3 deletions

diff --git a/docs/user-guide/06-interfaces-generics.md b/docs/user-guide/06-interfaces-generics.md
index 30efbada1..b7fca069e 100644
--- a/docs/user-guide/06-interfaces-generics.md
+++ b/docs/user-guide/06-interfaces-generics.md
@@ -1026,12 +1026,12 @@ void printNumbers<each T>(expand each T args) where T == int
 void compute<each T>(expand each T args) where T == int
 {
     // Maps every element in `args` to `elementValue + 1`, and forwards the
-    // new values as arguments to `printNumber`.
-    printNumber(expand (each args) + 1);
+    // new values as arguments to `printNumbers`.
+    printNumbers(expand (each args) + 1);
 
     // The above statement is equivalent to:
     // ```
-    // printNumber(args[0] + 1, args[1] + 1, ..., args[n-1] + 1);
+    // printNumbers(args[0] + 1, args[1] + 1, ..., args[n-1] + 1);
     // ```
 }
 void test()