diff --git a/src/ast/ast_type.cc b/src/ast/ast_type.cc
index 6dbf38b..c5d6871 100644
--- a/src/ast/ast_type.cc
+++ b/src/ast/ast_type.cc
@@ -58,13 +58,11 @@
 }
 
 bool Type::is_float_matrix() const {
-  return Is<Matrix>(
-      [](const Matrix* m) { return m->type()->is_float_scalar(); });
+  return Is([](const Matrix* m) { return m->type()->is_float_scalar(); });
 }
 
 bool Type::is_float_vector() const {
-  return Is<Vector>(
-      [](const Vector* v) { return v->type()->is_float_scalar(); });
+  return Is([](const Vector* v) { return v->type()->is_float_scalar(); });
 }
 
 bool Type::is_float_scalar_or_vector() const {
@@ -80,11 +78,11 @@
 }
 
 bool Type::is_unsigned_integer_vector() const {
-  return Is<Vector>([](const Vector* v) { return v->type()->Is<U32>(); });
+  return Is([](const Vector* v) { return v->type()->Is<U32>(); });
 }
 
 bool Type::is_signed_integer_vector() const {
-  return Is<Vector>([](const Vector* v) { return v->type()->Is<I32>(); });
+  return Is([](const Vector* v) { return v->type()->Is<I32>(); });
 }
 
 bool Type::is_unsigned_scalar_or_vector() const {
@@ -100,7 +98,7 @@
 }
 
 bool Type::is_bool_vector() const {
-  return Is<Vector>([](const Vector* v) { return v->type()->Is<Bool>(); });
+  return Is([](const Vector* v) { return v->type()->Is<Bool>(); });
 }
 
 bool Type::is_bool_scalar_or_vector() const {
diff --git a/src/castable.h b/src/castable.h
index d825de1..ed075b0 100644
--- a/src/castable.h
+++ b/src/castable.h
@@ -17,6 +17,8 @@
 
 #include <utility>
 
+#include "src/traits.h"
+
 #if defined(__clang__)
 /// Temporarily disable certain warnings when using Castable API
 #define TINT_CASTABLE_PUSH_DISABLE_WARNINGS()                               \
@@ -298,8 +300,9 @@
   /// pred(const TO*) returns true
   /// @param pred predicate function with signature `bool(const TO*)` called iff
   /// object is of, or derives from the class `TO`.
-  template <typename TO, int FLAGS = 0, typename Pred = detail::Infer>
+  template <int FLAGS = 0, typename Pred = detail::Infer>
   inline bool Is(Pred&& pred) const {
+    using TO = typename std::remove_pointer<traits::ParamTypeT<Pred, 0>>::type;
     return tint::Is<TO, FLAGS>(static_cast<const CLASS*>(this),
                                std::forward<Pred>(pred));
   }
diff --git a/src/castable_test.cc b/src/castable_test.cc
index 0d10aac..e44983b 100644
--- a/src/castable_test.cc
+++ b/src/castable_test.cc
@@ -214,17 +214,17 @@
 TEST(Castable, IsWithPredicate) {
   std::unique_ptr<Animal> frog = std::make_unique<Frog>();
 
-  frog->Is<Animal>([&frog](const Animal* a) {
+  frog->Is([&frog](const Animal* a) {
     EXPECT_EQ(a, frog.get());
     return true;
   });
 
-  ASSERT_TRUE((frog->Is<Animal>([](const Animal*) { return true; })));
-  ASSERT_FALSE((frog->Is<Animal>([](const Animal*) { return false; })));
+  ASSERT_TRUE((frog->Is([](const Animal*) { return true; })));
+  ASSERT_FALSE((frog->Is([](const Animal*) { return false; })));
 
   // Predicate not called if cast is invalid
   auto expect_not_called = [] { FAIL() << "Should not be called"; };
-  ASSERT_FALSE((frog->Is<Bear>([&](const Animal*) {
+  ASSERT_FALSE((frog->Is([&](const Bear*) {
     expect_not_called();
     return true;
   })));
diff --git a/src/intrinsic_table.cc b/src/intrinsic_table.cc
index 970a9dd..0f497ef 100644
--- a/src/intrinsic_table.cc
+++ b/src/intrinsic_table.cc
@@ -483,7 +483,7 @@
   if (ty->Is<Any>()) {
     return true;
   }
-  return ty->Is<sem::Sampler>([](const sem::Sampler* s) {
+  return ty->Is([](const sem::Sampler* s) {
     return s->kind() == ast::SamplerKind::kSampler;
   });
 }
@@ -496,7 +496,7 @@
   if (ty->Is<Any>()) {
     return true;
   }
-  return ty->Is<sem::Sampler>([](const sem::Sampler* s) {
+  return ty->Is([](const sem::Sampler* s) {
     return s->kind() == ast::SamplerKind::kComparisonSampler;
   });
 }
@@ -575,7 +575,7 @@
   if (ty->Is<Any>()) {
     return true;
   }
-  return ty->Is<sem::DepthTexture>([&](auto t) { return t->dim() == dim; });
+  return ty->Is([&](const sem::DepthTexture* t) { return t->dim() == dim; });
 }
 
 #define DECLARE_DEPTH_TEXTURE(suffix, dim)                       \
@@ -597,8 +597,9 @@
   if (ty->Is<Any>()) {
     return true;
   }
-  return ty->Is<sem::DepthMultisampledTexture>(
-      [&](auto t) { return t->dim() == ast::TextureDimension::k2d; });
+  return ty->Is([&](const sem::DepthMultisampledTexture* t) {
+    return t->dim() == ast::TextureDimension::k2d;
+  });
 }
 
 sem::DepthMultisampledTexture* build_texture_depth_multisampled_2d(
diff --git a/src/reader/spirv/parser_type.cc b/src/reader/spirv/parser_type.cc
index 9b3e527..7802bad 100644
--- a/src/reader/spirv/parser_type.cc
+++ b/src/reader/spirv/parser_type.cc
@@ -367,7 +367,7 @@
 }
 
 bool Type::IsFloatVector() const {
-  return Is<Vector>([](const Vector* v) { return v->type->IsFloatScalar(); });
+  return Is([](const Vector* v) { return v->type->IsFloatScalar(); });
 }
 
 bool Type::IsIntegerScalar() const {
@@ -383,7 +383,7 @@
 }
 
 bool Type::IsSignedIntegerVector() const {
-  return Is<Vector>([](const Vector* v) { return v->type->Is<I32>(); });
+  return Is([](const Vector* v) { return v->type->Is<I32>(); });
 }
 
 bool Type::IsSignedScalarOrVector() const {
@@ -391,7 +391,7 @@
 }
 
 bool Type::IsUnsignedIntegerVector() const {
-  return Is<Vector>([](const Vector* v) { return v->type->Is<U32>(); });
+  return Is([](const Vector* v) { return v->type->Is<U32>(); });
 }
 
 bool Type::IsUnsignedScalarOrVector() const {
diff --git a/src/sem/type.cc b/src/sem/type.cc
index 5f547a2..158fb73 100644
--- a/src/sem/type.cc
+++ b/src/sem/type.cc
@@ -77,13 +77,11 @@
 }
 
 bool Type::is_float_matrix() const {
-  return Is<Matrix>(
-      [](const Matrix* m) { return m->type()->is_float_scalar(); });
+  return Is([](const Matrix* m) { return m->type()->is_float_scalar(); });
 }
 
 bool Type::is_float_vector() const {
-  return Is<Vector>(
-      [](const Vector* v) { return v->type()->is_float_scalar(); });
+  return Is([](const Vector* v) { return v->type()->is_float_scalar(); });
 }
 
 bool Type::is_float_scalar_or_vector() const {
@@ -107,11 +105,11 @@
 }
 
 bool Type::is_signed_integer_vector() const {
-  return Is<Vector>([](const Vector* v) { return v->type()->Is<I32>(); });
+  return Is([](const Vector* v) { return v->type()->Is<I32>(); });
 }
 
 bool Type::is_unsigned_integer_vector() const {
-  return Is<Vector>([](const Vector* v) { return v->type()->Is<U32>(); });
+  return Is([](const Vector* v) { return v->type()->Is<U32>(); });
 }
 
 bool Type::is_unsigned_scalar_or_vector() const {
@@ -127,7 +125,7 @@
 }
 
 bool Type::is_bool_vector() const {
-  return Is<Vector>([](const Vector* v) { return v->type()->Is<Bool>(); });
+  return Is([](const Vector* v) { return v->type()->Is<Bool>(); });
 }
 
 bool Type::is_bool_scalar_or_vector() const {
@@ -135,12 +133,11 @@
 }
 
 bool Type::is_numeric_vector() const {
-  return Is<Vector>(
-      [](const Vector* v) { return v->type()->is_numeric_scalar(); });
+  return Is([](const Vector* v) { return v->type()->is_numeric_scalar(); });
 }
 
 bool Type::is_scalar_vector() const {
-  return Is<Vector>([](const Vector* v) { return v->type()->is_scalar(); });
+  return Is([](const Vector* v) { return v->type()->is_scalar(); });
 }
 
 bool Type::is_numeric_scalar_or_vector() const {