diff --git a/cpp2rust/rule_preprocessing/cpp_rule_indexer.cpp b/cpp2rust/rule_preprocessing/cpp_rule_indexer.cpp
index 346045ec5..3ccf98225 100644
--- a/cpp2rust/rule_preprocessing/cpp_rule_indexer.cpp
+++ b/cpp2rust/rule_preprocessing/cpp_rule_indexer.cpp
@@ -49,6 +49,9 @@ std::string ClassOf(clang::QualType type) {
       return ClassOf(clang::QualType(qualifier.getAsType(), 0));
     }
   }
+  if (auto tag = type->getAsTagDecl()) {
+    return RulesLoader::ClassKey(tag);
+  }
   return {};
 }
 
diff --git a/rule-preprocessor/src/syntactic.rs b/rule-preprocessor/src/syntactic.rs
index f56a31fd0..608322a31 100644
--- a/rule-preprocessor/src/syntactic.rs
+++ b/rule-preprocessor/src/syntactic.rs
@@ -383,11 +383,10 @@ impl<'a> FnIrBuilder<'a> {
             for pred in wc.predicates() {
                 let Some(ty) = pred.ty() else { continue };
                 let name = ty.syntax().text().to_string();
-                let bounds = extract_bounds(pred.type_bound_list());
-                generics
-                    .entry(name)
-                    .and_modify(|existing| existing.extend(bounds.clone()))
-                    .or_insert(bounds);
+                let Some(existing) = generics.get_mut(&name) else {
+                    continue;
+                };
+                existing.extend(extract_bounds(pred.type_bound_list()));
             }
         }
 
diff --git a/rules/cstddef/src_cxx17.cpp b/rules/cstddef/src_cxx17.cpp
index 43a02e0e1..97d83a7ca 100644
--- a/rules/cstddef/src_cxx17.cpp
+++ b/rules/cstddef/src_cxx17.cpp
@@ -12,3 +12,5 @@ std::byte f2(const std::byte &a0, unsigned a1) { return a0 >> a1; }
 std::byte f3(std::byte &a0, unsigned a1) { return a0 <<= a1; }
 
 std::byte f4(std::byte &a0, unsigned a1) { return a0 >>= a1; }
+
+template <typename T1> std::byte f5(std::byte a0, T1 a1) { return a0 << a1; }
diff --git a/rules/cstddef/tgt_unsafe.rs b/rules/cstddef/tgt_unsafe.rs
index 573487aaa..8b58d3acb 100644
--- a/rules/cstddef/tgt_unsafe.rs
+++ b/rules/cstddef/tgt_unsafe.rs
@@ -48,3 +48,10 @@ fn f4(a0: &mut u8, a1: u32) -> u8 {
     *a0 = n_;
     *a0
 }
+
+fn f5<T1>(a0: u8, a1: T1) -> u8
+where
+    u8: ::std::ops::Shl<T1, Output = u8>,
+{
+    a0 << a1
+}
diff --git a/tests/unit/byte.cpp b/tests/unit/byte.cpp
index 14ca152ae..b308b937e 100644
--- a/tests/unit/byte.cpp
+++ b/tests/unit/byte.cpp
@@ -19,5 +19,9 @@ int main() {
   unsigned ushift4 = 3;
   b1 >>= ushift4;
   assert(b1 == std::byte(0x04));
+
+  int ishift = 1;
+  std::byte shl2 = b1 << ishift;
+  assert(shl2 == std::byte(0x08));
   return 0;
 }
diff --git a/tests/unit/out/refcount/byte.rs b/tests/unit/out/refcount/byte.rs
index 4b56680ee..d4ce70a8a 100644
--- a/tests/unit/out/refcount/byte.rs
+++ b/tests/unit/out/refcount/byte.rs
@@ -32,6 +32,9 @@ fn main_0() -> i32 {
         b1
     };
     assert!((b1 == ((4) as u8)));
+    let mut ishift: i32 = 1;
+    let mut shl2: u8 = b1 << ishift;
+    assert!((shl2 == ((8) as u8)));
     return 0;
 }
 pub fn __cpp2rust_init_globals() {}
diff --git a/tests/unit/out/unsafe/byte.rs b/tests/unit/out/unsafe/byte.rs
index eb4a39207..dced97ec2 100644
--- a/tests/unit/out/unsafe/byte.rs
+++ b/tests/unit/out/unsafe/byte.rs
@@ -34,6 +34,9 @@ unsafe fn main_0() -> i32 {
         b1
     };
     assert!(((b1) == ((4) as u8)));
+    let mut ishift: i32 = 1;
+    let mut shl2: u8 = b1 << ishift;
+    assert!(((shl2) == ((8) as u8)));
     return 0;
 }
 pub unsafe fn __cpp2rust_init_globals() {}