From ace8cca5ac6b4465d14e94547e0896cb88c99012 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johel=20Ernesto=20Guerrero=20Pe=C3=B1a?=
 <johelegp@gmail.com>
Date: Wed, 2 Oct 2024 12:38:31 -0400
Subject: [PATCH] fix(to_cpp1): improve recognition of dependent types and
 deducible parameters

---
 ...pure2-bugfix-for-deducible-parameters.cpp2 |  32 ++
 ...-bugfix-for-dependent-types-recursion.cpp2 |   6 +
 .../pure2-bugfix-for-dependent-types.cpp2     |  95 ++++
 .../pure2-bugfix-for-deducible-parameters.cpp |  90 ++++
 ...ugfix-for-deducible-parameters.cpp2.output |   2 +
 ...2-bugfix-for-dependent-types-recursion.cpp |  27 +
 ...-for-dependent-types-recursion.cpp2.output |   2 +
 .../pure2-bugfix-for-dependent-types.cpp      | 133 +++++
 ...re2-bugfix-for-dependent-types.cpp2.output |   2 +
 source/parse.h                                |  28 +-
 source/to_cpp1.h                              | 464 +++++++++++++++---
 11 files changed, 798 insertions(+), 83 deletions(-)
 create mode 100644 regression-tests/pure2-bugfix-for-deducible-parameters.cpp2
 create mode 100644 regression-tests/pure2-bugfix-for-dependent-types-recursion.cpp2
 create mode 100644 regression-tests/pure2-bugfix-for-dependent-types.cpp2
 create mode 100644 regression-tests/test-results/pure2-bugfix-for-deducible-parameters.cpp
 create mode 100644 regression-tests/test-results/pure2-bugfix-for-deducible-parameters.cpp2.output
 create mode 100644 regression-tests/test-results/pure2-bugfix-for-dependent-types-recursion.cpp
 create mode 100644 regression-tests/test-results/pure2-bugfix-for-dependent-types-recursion.cpp2.output
 create mode 100644 regression-tests/test-results/pure2-bugfix-for-dependent-types.cpp
 create mode 100644 regression-tests/test-results/pure2-bugfix-for-dependent-types.cpp2.output

diff --git a/regression-tests/pure2-bugfix-for-deducible-parameters.cpp2 b/regression-tests/pure2-bugfix-for-deducible-parameters.cpp2
new file mode 100644
index 000000000..a3b4c7628
--- /dev/null
+++ b/regression-tests/pure2-bugfix-for-deducible-parameters.cpp2
@@ -0,0 +1,32 @@
+// Dependent, non-deducible parameters are wrapped like non-dependent parameters.
+init: <T> (out x: std::integral_constant<i32, T::value>) = { x = (); }
+init: <T> (out x: std::integral_constant<i32, T::value>, _: T) = { x = (); }
+id: <T> (x: std::integral_constant<i32, T::value>) -> forward _ = x;
+id: <T> (x: std::integral_constant<i32, T::value>, y: T) = { assert(x& == y&); }
+
+main: () = {
+  zero: type == std::integral_constant<i32, 0>;
+
+  z: zero;
+  init<zero>(out z);
+  assert(id<zero>(z)& == z&);
+
+  // Deducible parameters.
+  _ = :v                   = 0;
+  :<T> (_: std::vector<T>) = {}(:std::vector<i32> = ());
+  :<T> (_: std::vector<std::vector<T>>) = {}(:std::vector<std::vector<i32>> = ());
+  // _ = :<T, U> (x: std::pair<T, typename U::value_type>, y: U) = {}(:std::pair = (0, 0), z); // Blocked on #727.
+  :<T, U> (_: std::array<T, U::value>, _: U) = {}(:std::array<i32, 0> = (), z);
+  init(out z, z);
+  id(z, z);
+
+  // Test that these are emitted unwrapped in case they are deducible.
+  (copy f := :<T> (_: std::vector<std::type_identity_t<T>>) = {})
+    static_assert(!std::is_invocable_v<decltype(f), std::vector<i32>>, "`T` is non-deducible.");
+  (copy f := :<T> (_: std::vector<std::vector<T>>) = {})
+    static_assert(std::is_invocable_v<decltype(f), std::vector<std::vector<i32>>>, "`T` is deducible.");
+}
+
+v: <T> type = {
+  operator=: (out this, _: T) = { }
+}
diff --git a/regression-tests/pure2-bugfix-for-dependent-types-recursion.cpp2 b/regression-tests/pure2-bugfix-for-dependent-types-recursion.cpp2
new file mode 100644
index 000000000..d449b8d55
--- /dev/null
+++ b/regression-tests/pure2-bugfix-for-dependent-types-recursion.cpp2
@@ -0,0 +1,6 @@
+main: () = {
+  a: type == b;
+  b: type == a;
+  _ = a::t;
+  _ = b::t;
+}
diff --git a/regression-tests/pure2-bugfix-for-dependent-types.cpp2 b/regression-tests/pure2-bugfix-for-dependent-types.cpp2
new file mode 100644
index 000000000..da010bbb4
--- /dev/null
+++ b/regression-tests/pure2-bugfix-for-dependent-types.cpp2
@@ -0,0 +1,95 @@
+identity: <T> type == T;
+
+f: <T, V: T::value_type> (x: T::value_type) -> T::value_type = {
+  assert(x is T::value_type);
+  y: T::value_type;
+  y = x;
+  z: type == T::value_type;
+  return (:T::value_type = x);
+
+  // Dependent *template-id*s.
+  _ = :identity<T>::value_type = ();      // First identifier.
+  _ = :std::optional<T>::value_type = (); // Non-first identifier.
+  _ = :std::array<i32, T::value>::value_type = ();
+  _ = :std::array<i32, T::value + T::value>::value_type = ();
+
+  // Emitted `template`.
+  ptr: type  == * T; // Also test lookup through type aliases.
+  nptr: type == * i32;
+  _ = :std::pointer_traits<ptr>::rebind<ptr> = ();   // Type-only context.
+  _ = :std::pointer_traits<nptr>::rebind<nptr> = (); // Non-dependent.
+  _ = :std::pointer_traits<nptr>::rebind<ptr> = ();  // Dependent on the nested template.
+  _ = :std::pointer_traits<ptr>::rebind<nptr> = ();  // Dependent on the outer template.
+  // _ = :identity<typename std::pointer_traits<ptr>::rebind<ptr>> = (); // Non type-only context. Blocked on #727.
+
+  // Aliases.
+  w: type == T;
+  _ = :w::value_type = x;
+  v: type == w;
+  _ = :v::value_type = x;
+  a: type == T::type;
+  _ = :a::value_type = x;
+
+  {
+    // Test that there's no prefixed `typename` to....
+    _ = std::integral_constant<i32, T::value>(); // `T::value`.
+    _ = :std::type_identity_t<T> = ();           // `std::type_identity_t<T>`.
+
+    // Test that non-dependent names aren't emitted with `typename`.
+    a: type == std::integral_constant<i32, 0>;
+    b: type == a;
+    c: type == b;
+    _ = :b::value_type = x;
+    _ = :c::value_type = x;
+  }
+}
+
+t: @cpp1_rule_of_zero <T: type> type = {
+  u: type = {
+    x: T::value_type = ();
+    this: T::type    = ();
+    // Test that there's no 'typename' in the member initializer list.
+    operator=: (out this, that) = { }
+  }
+  x: T::value_type = 0;
+}
+
+main: () = {
+  zero: type == std::integral_constant<i32, 0>;
+  _ = f<zero, 0>(0);
+
+  // clang-format off
+  _ = : ::t<zero> = (); // clang-format on
+
+  // Emitted `template` (noop, taken care of by the UFCS macro).
+  // _ = :(move f) = f.operator()<i32>();(:<T> () = {}); // Blocked on #832.
+
+  // Nesting is not relevant to lookup.
+  _ = :<T> () = { _ = :T::value_type = (); };
+  _ = :() = { _ = :<T> () = { _ = :T::value_type = (); }; };
+  _ = :() = { _ = :() = { _ = :<T> () = { _ = :T::value_type = (); }; }; };
+  _ = :() = { _ = :() = { _ = :() = { _ = :<T> () = { _ = :T::value_type = (); }; }; }; };
+  _ = :() = { _ = :() = { _ = :<T> () = { _ = :() = { _ = :T::value_type = (); }; }; }; };
+  _ = :() = { _ = :<T> () = { _ = :() = { _ = :() = { _ = :T::value_type = (); }; }; }; };
+  _ = :<T> () = { _ = :() = { _ = :() = { _ = :() = { _ = :T::value_type = (); }; }; }; };
+  _ = :<T> () = { _ = :() = { _ = :() = { _ = :(_: T::value_type) = {}; }; }; };
+  _ = :<T> () = { _ = :() = { _ = :(_: T::value_type) = { _ = :() = {}; }; }; };
+  _ = :<T> () = { _ = :(_: T::value_type) = { _ = :() = { _ = :() = {}; }; }; };
+  _ = :<T> (_: T::value_type) = { _ = :() = { _ = :() = { _ = :() = {}; }; }; };
+
+  // Lookup.
+  {
+    alias: type == std::integral_constant<i32, 0>;
+    _ = :alias::value_type = 0; // Non-dependent.
+  }
+  _ = :<T> (_: T) = {
+    alias: type == std::integral_constant<T, 0>;
+    _ = :alias::value_type = 0; // Dependent.
+    {
+      alias: type == std::integral_constant<i32, 0>;
+      _ = :alias::value_type = 0; // Non-dependent.
+    }
+  }(0);
+
+  _ = :(r) -> std::type_identity_t<decltype(begin(r)*)> = r[0];(std::vector<int>(1));
+}
diff --git a/regression-tests/test-results/pure2-bugfix-for-deducible-parameters.cpp b/regression-tests/test-results/pure2-bugfix-for-deducible-parameters.cpp
new file mode 100644
index 000000000..c1a5c5729
--- /dev/null
+++ b/regression-tests/test-results/pure2-bugfix-for-deducible-parameters.cpp
@@ -0,0 +1,90 @@
+
+#define CPP2_IMPORT_STD          Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+#line 1 "pure2-bugfix-for-deducible-parameters.cpp2"
+
+#line 30 "pure2-bugfix-for-deducible-parameters.cpp2"
+template<typename T> class v;
+  
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-bugfix-for-deducible-parameters.cpp2"
+// Dependent, non-deducible parameters are wrapped like non-dependent parameters.
+#line 2 "pure2-bugfix-for-deducible-parameters.cpp2"
+template<typename T> auto init(cpp2::impl::out<std::integral_constant<cpp2::i32,T::value>> x) -> void;
+template<typename T> auto init(cpp2::impl::out<std::integral_constant<cpp2::i32,T::value>> x, [[maybe_unused]] T const& unnamed_param_2) -> void;
+template<typename T> [[nodiscard]] auto id(cpp2::impl::in<std::integral_constant<cpp2::i32,T::value>> x) -> auto&&;
+template<typename T> auto id(cpp2::impl::in<std::integral_constant<cpp2::i32,T::value>> x, T const& y) -> void;
+
+auto main() -> int;
+
+#line 30 "pure2-bugfix-for-deducible-parameters.cpp2"
+template<typename T> class v {
+  public: explicit v([[maybe_unused]] T const& unnamed_param_2);
+#line 31 "pure2-bugfix-for-deducible-parameters.cpp2"
+  public: auto operator=([[maybe_unused]] T const& unnamed_param_2) -> v& ;
+  public: v(v const&) = delete; /* No 'that' constructor, suppress copy */
+  public: auto operator=(v const&) -> void = delete;
+
+#line 32 "pure2-bugfix-for-deducible-parameters.cpp2"
+};
+
+
+//=== Cpp2 function definitions =================================================
+
+#line 1 "pure2-bugfix-for-deducible-parameters.cpp2"
+
+#line 2 "pure2-bugfix-for-deducible-parameters.cpp2"
+template<typename T> auto init(cpp2::impl::out<std::integral_constant<cpp2::i32,T::value>> x) -> void{x.construct(); }
+#line 3 "pure2-bugfix-for-deducible-parameters.cpp2"
+template<typename T> auto init(cpp2::impl::out<std::integral_constant<cpp2::i32,T::value>> x, [[maybe_unused]] T const& unnamed_param_2) -> void{x.construct(); }
+#line 4 "pure2-bugfix-for-deducible-parameters.cpp2"
+template<typename T> [[nodiscard]] auto id(cpp2::impl::in<std::integral_constant<cpp2::i32,T::value>> x) -> auto&& { return x;  }
+#line 5 "pure2-bugfix-for-deducible-parameters.cpp2"
+template<typename T> auto id(cpp2::impl::in<std::integral_constant<cpp2::i32,T::value>> x, T const& y) -> void{if (cpp2::cpp2_default.is_active() && !(&x == &y) ) { cpp2::cpp2_default.report_violation(""); }}
+
+#line 7 "pure2-bugfix-for-deducible-parameters.cpp2"
+auto main() -> int{
+  using zero = std::integral_constant<cpp2::i32,0>;
+
+  cpp2::impl::deferred_init<zero> z; 
+  init<zero>(cpp2::impl::out(&z));
+  if (cpp2::cpp2_default.is_active() && !(&id<zero>(z.value()) == &z.value()) ) { cpp2::cpp2_default.report_violation(""); }
+
+  // Deducible parameters.
+  static_cast<void>(v{  0});
+  []<typename T>([[maybe_unused]] std::vector<T> const& unnamed_param_1) -> void{}(std::vector<cpp2::i32>{});
+  []<typename T>([[maybe_unused]] std::vector<std::vector<T>> const& unnamed_param_1) -> void{}(std::vector<std::vector<cpp2::i32>>{});
+  // _ = :<T, U> (x: std::pair<T, typename U::value_type>, y: U) = {}(:std::pair = (0, 0), z); // Blocked on #727.
+  []<typename T, typename U>([[maybe_unused]] std::array<T,U::value> const& unnamed_param_1, [[maybe_unused]] U const& unnamed_param_2) -> void{}(std::array<cpp2::i32,0>{}, z.value());
+  init(cpp2::impl::out(&z.value()), z.value());
+  id(z.value(), cpp2::move(z.value()));
+{
+auto f{[]<typename T>([[maybe_unused]] std::vector<std::type_identity_t<T>> const& unnamed_param_1) -> void{}};
+
+  // Test that these are emitted unwrapped in case they are deducible.
+
+#line 25 "pure2-bugfix-for-deducible-parameters.cpp2"
+    static_assert(!(std::is_invocable_v<decltype(cpp2::move(f)),std::vector<cpp2::i32>>), "`T` is non-deducible.");
+}
+{
+auto f{[]<typename T>([[maybe_unused]] std::vector<std::vector<T>> const& unnamed_param_1) -> void{}};
+
+#line 27 "pure2-bugfix-for-deducible-parameters.cpp2"
+    static_assert(std::is_invocable_v<decltype(cpp2::move(f)),std::vector<std::vector<cpp2::i32>>>, "`T` is deducible.");
+}
+#line 28 "pure2-bugfix-for-deducible-parameters.cpp2"
+}
+
+#line 31 "pure2-bugfix-for-deducible-parameters.cpp2"
+  template <typename T> v<T>::v([[maybe_unused]] T const& unnamed_param_2){}
+#line 31 "pure2-bugfix-for-deducible-parameters.cpp2"
+  template <typename T> auto v<T>::operator=([[maybe_unused]] T const& unnamed_param_2) -> v& {
+                                  return *this; }
+
diff --git a/regression-tests/test-results/pure2-bugfix-for-deducible-parameters.cpp2.output b/regression-tests/test-results/pure2-bugfix-for-deducible-parameters.cpp2.output
new file mode 100644
index 000000000..7e84d47be
--- /dev/null
+++ b/regression-tests/test-results/pure2-bugfix-for-deducible-parameters.cpp2.output
@@ -0,0 +1,2 @@
+pure2-bugfix-for-deducible-parameters.cpp2... ok (all Cpp2, passes safety checks)
+
diff --git a/regression-tests/test-results/pure2-bugfix-for-dependent-types-recursion.cpp b/regression-tests/test-results/pure2-bugfix-for-dependent-types-recursion.cpp
new file mode 100644
index 000000000..d04857dc5
--- /dev/null
+++ b/regression-tests/test-results/pure2-bugfix-for-dependent-types-recursion.cpp
@@ -0,0 +1,27 @@
+
+#define CPP2_IMPORT_STD          Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+#line 1 "pure2-bugfix-for-dependent-types-recursion.cpp2"
+
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-bugfix-for-dependent-types-recursion.cpp2"
+auto main() -> int;
+
+//=== Cpp2 function definitions =================================================
+
+#line 1 "pure2-bugfix-for-dependent-types-recursion.cpp2"
+auto main() -> int{
+#line 2 "pure2-bugfix-for-dependent-types-recursion.cpp2"
+  using a = b;
+  using b = a;
+  static_cast<void>(a::t);
+  static_cast<void>(b::t);
+}
+
diff --git a/regression-tests/test-results/pure2-bugfix-for-dependent-types-recursion.cpp2.output b/regression-tests/test-results/pure2-bugfix-for-dependent-types-recursion.cpp2.output
new file mode 100644
index 000000000..759bf8d53
--- /dev/null
+++ b/regression-tests/test-results/pure2-bugfix-for-dependent-types-recursion.cpp2.output
@@ -0,0 +1,2 @@
+pure2-bugfix-for-dependent-types-recursion.cpp2... ok (all Cpp2, passes safety checks)
+
diff --git a/regression-tests/test-results/pure2-bugfix-for-dependent-types.cpp b/regression-tests/test-results/pure2-bugfix-for-dependent-types.cpp
new file mode 100644
index 000000000..51c5e3f8f
--- /dev/null
+++ b/regression-tests/test-results/pure2-bugfix-for-dependent-types.cpp
@@ -0,0 +1,133 @@
+
+#define CPP2_IMPORT_STD          Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+#line 1 "pure2-bugfix-for-dependent-types.cpp2"
+
+#line 47 "pure2-bugfix-for-dependent-types.cpp2"
+template<typename T> class t;
+  
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-bugfix-for-dependent-types.cpp2"
+template<typename T> using identity = T;
+#line 2 "pure2-bugfix-for-dependent-types.cpp2"
+
+template<typename T, T::value_type V> [[nodiscard]] auto f(cpp2::impl::in<typename T::value_type> x) -> T::value_type;
+
+#line 47 "pure2-bugfix-for-dependent-types.cpp2"
+template<typename T> class t {
+struct u_x_as_base { typename T::value_type x; };
+
+#line 48 "pure2-bugfix-for-dependent-types.cpp2"
+  public: class u: public u_x_as_base, public T::type {
+
+#line 51 "pure2-bugfix-for-dependent-types.cpp2"
+    // Test that there's no 'typename' in the member initializer list.
+    public: u(u const& that);
+  };
+  private: T::value_type x {0}; 
+};
+
+auto main() -> int;
+
+//=== Cpp2 function definitions =================================================
+
+#line 1 "pure2-bugfix-for-dependent-types.cpp2"
+
+#line 3 "pure2-bugfix-for-dependent-types.cpp2"
+template<typename T, T::value_type V> [[nodiscard]] auto f(cpp2::impl::in<typename T::value_type> x) -> T::value_type{
+  if (cpp2::cpp2_default.is_active() && !(cpp2::impl::is<typename T::value_type>(x)) ) { cpp2::cpp2_default.report_violation(""); }
+  cpp2::impl::deferred_init<typename T::value_type> y; 
+  y.construct(x);
+  using z = T::value_type;
+  return { typename T::value_type{x} }; 
+
+  // Dependent *template-id*s.
+  static_cast<void>(typename identity<T>::value_type{});// First identifier.
+  static_cast<void>(typename std::optional<T>::value_type{});// Non-first identifier.
+  static_cast<void>(typename std::array<cpp2::i32,T::value>::value_type{});
+  static_cast<void>(typename std::array<cpp2::i32,T::value + T::value>::value_type{});
+
+  // Emitted `template`.
+  using ptr = T*;    // Also test lookup through type aliases.
+  using nptr = cpp2::i32*;
+  static_cast<void>(typename std::pointer_traits<ptr>::template rebind<ptr>{});// Type-only context.
+  static_cast<void>(std::pointer_traits<nptr>::rebind<nptr>{});// Non-dependent.
+  static_cast<void>(std::pointer_traits<nptr>::rebind<ptr>{});// Dependent on the nested template.
+  static_cast<void>(typename std::pointer_traits<ptr>::template rebind<nptr>{});// Dependent on the outer template.
+  // _ = :identity<typename std::pointer_traits<ptr>::rebind<ptr>> = (); // Non type-only context. Blocked on #727.
+
+  // Aliases.
+  using w = T;
+  static_cast<void>(typename w::value_type{x});
+  using v = w;
+  static_cast<void>(typename v::value_type{x});
+  using a = T::type;
+  static_cast<void>(typename a::value_type{x});
+
+  {
+    // Test that there's no prefixed `typename` to....
+    static_cast<void>(std::integral_constant<cpp2::i32,T::value>());// `T::value`.
+    static_cast<void>(std::type_identity_t<T>{});// `std::type_identity_t<T>`.
+
+    // Test that non-dependent names aren't emitted with `typename`.
+    using a = std::integral_constant<cpp2::i32,0>;
+    using b = a;
+    using c = b;
+    static_cast<void>(b::value_type{x});
+    static_cast<void>(c::value_type{x});
+  }
+}
+
+#line 52 "pure2-bugfix-for-dependent-types.cpp2"
+    template <typename T> t<T>::u::u(u const& that)
+                                    : u_x_as_base{ that.x }
+                                    , T::type{ static_cast<typename T::type const&>(that) }{}
+
+#line 57 "pure2-bugfix-for-dependent-types.cpp2"
+auto main() -> int{
+  using zero = std::integral_constant<cpp2::i32,0>;
+  static_cast<void>(f<zero,0>(0));
+
+  // clang-format off
+  static_cast<void>(::t<zero>{});// clang-format on
+
+  // Emitted `template` (noop, taken care of by the UFCS macro).
+  // _ = :(move f) = f.operator()<i32>();(:<T> () = {}); // Blocked on #832.
+
+  // Nesting is not relevant to lookup.
+  static_cast<void>([]<typename T>() -> void{static_cast<void>(typename T::value_type{}); });
+  static_cast<void>([]() -> void{static_cast<void>([]<typename T>() -> void{static_cast<void>(typename T::value_type{}); }); });
+  static_cast<void>([]() -> void{static_cast<void>([]() -> void{static_cast<void>([]<typename T>() -> void{static_cast<void>(typename T::value_type{}); }); }); });
+  static_cast<void>([]() -> void{static_cast<void>([]() -> void{static_cast<void>([]() -> void{static_cast<void>([]<typename T>() -> void{static_cast<void>(typename T::value_type{}); }); }); }); });
+  static_cast<void>([]() -> void{static_cast<void>([]() -> void{static_cast<void>([]<typename T>() -> void{static_cast<void>([]() -> void{static_cast<void>(typename T::value_type{}); }); }); }); });
+  static_cast<void>([]() -> void{static_cast<void>([]<typename T>() -> void{static_cast<void>([]() -> void{static_cast<void>([]() -> void{static_cast<void>(typename T::value_type{}); }); }); }); });
+  static_cast<void>([]<typename T>() -> void{static_cast<void>([]() -> void{static_cast<void>([]() -> void{static_cast<void>([]() -> void{static_cast<void>(typename T::value_type{}); }); }); }); });
+  static_cast<void>([]<typename T>() -> void{static_cast<void>([]() -> void{static_cast<void>([]() -> void{static_cast<void>([]([[maybe_unused]] cpp2::impl::in<typename T::value_type> unnamed_param_1) -> void{}); }); }); });
+  static_cast<void>([]<typename T>() -> void{static_cast<void>([]() -> void{static_cast<void>([]([[maybe_unused]] cpp2::impl::in<typename T::value_type> unnamed_param_1) -> void{static_cast<void>([]() -> void{}); }); }); });
+  static_cast<void>([]<typename T>() -> void{static_cast<void>([]([[maybe_unused]] cpp2::impl::in<typename T::value_type> unnamed_param_1) -> void{static_cast<void>([]() -> void{static_cast<void>([]() -> void{}); }); }); });
+  static_cast<void>([]<typename T>([[maybe_unused]] cpp2::impl::in<typename T::value_type> unnamed_param_1) -> void{static_cast<void>([]() -> void{static_cast<void>([]() -> void{static_cast<void>([]() -> void{}); }); }); });
+
+  // Lookup.
+  {
+    using alias = std::integral_constant<cpp2::i32,0>;
+    static_cast<void>(alias::value_type{0});// Non-dependent.
+  }
+  static_cast<void>([]<typename T>([[maybe_unused]] T const& unnamed_param_1) -> void{
+    using alias = std::integral_constant<T,0>;
+    static_cast<void>(typename alias::value_type{0});// Dependent.
+    {
+      using alias = std::integral_constant<cpp2::i32,0>;
+      static_cast<void>(alias::value_type{0});// Non-dependent.
+    }
+  }(0));
+
+  static_cast<void>([](auto const& r) -> std::type_identity_t<decltype(*cpp2::impl::assert_not_null(begin(r)))> { return CPP2_ASSERT_IN_BOUNDS_LITERAL(r, 0);  }(std::vector<int>(1)));
+}
+
diff --git a/regression-tests/test-results/pure2-bugfix-for-dependent-types.cpp2.output b/regression-tests/test-results/pure2-bugfix-for-dependent-types.cpp2.output
new file mode 100644
index 000000000..6896db60e
--- /dev/null
+++ b/regression-tests/test-results/pure2-bugfix-for-dependent-types.cpp2.output
@@ -0,0 +1,2 @@
+pure2-bugfix-for-dependent-types.cpp2... ok (all Cpp2, passes safety checks)
+
diff --git a/source/parse.h b/source/parse.h
index 44d45c9d6..b84f0d399 100644
--- a/source/parse.h
+++ b/source/parse.h
@@ -217,7 +217,7 @@ struct literal_node {
             if (
                 !std::exchange(first, false)
                 && p->as_string_view().starts_with("\"")
-                ) 
+                )
             {
                 ret += " ";
             }
@@ -1376,6 +1376,8 @@ struct type_id_node
 
     std::unique_ptr<type_id_node> constraint = {};
 
+    bool type_only_context = false;
+
     // Out-of-line definition of the dtor is necessary due to the forward-declared
     // type(s) used in a std::unique_ptr as a member
     ~type_id_node();
@@ -2386,7 +2388,7 @@ struct parameter_declaration_list_node
 
     std::vector<std::unique_ptr<parameter_declaration_node>> parameters;
 
-    parameter_declaration_list_node(bool f = false, bool t = false, bool s = false) 
+    parameter_declaration_list_node(bool f = false, bool t = false, bool s = false)
         : in_function_typeid{f}
         , in_template_param_list{t}
         , in_statement_param_list{s}
@@ -2502,7 +2504,7 @@ struct function_type_node
         assert (parameters);
 
         auto ret = parameters->to_string();
-        
+
         if (throws) {
             ret += " throws";
         }
@@ -5833,7 +5835,7 @@ class parser
     //
     //  errors      error list
     //
-    parser( 
+    parser(
         std::vector<error_entry>& errors_,
         std::set<std::string>&    includes_
     )
@@ -6296,9 +6298,9 @@ class parser
                 //  Next should be an expression-list followed by a ')'
                 //  If not, then this wasn't a call expression so backtrack to
                 //  the '(' which will be part of the next grammar production
-		        is_inside_call_expr = true;
+            is_inside_call_expr = true;
                 term.expr_list = expression_list(term.op, lexeme::RightParen);
-		        is_inside_call_expr = false;
+            is_inside_call_expr = false;
 
                 if (
                     term.expr_list
@@ -6327,7 +6329,7 @@ class parser
                 }
             }
             else if (
-                ( 
+                (
                     term.op->type() == lexeme::EllipsisLess
                     || term.op->type() == lexeme::EllipsisEqual
                     )
@@ -6882,11 +6884,13 @@ class parser
     auto type_id(
         bool allow_omitting_type_name = false,
         bool allow_constraint         = false,
-        bool allow_function_type      = false
+        bool allow_function_type      = false,
+        bool type_only_context        = true
     )
         -> std::unique_ptr<type_id_node>
     {
         auto n = std::make_unique<type_id_node>();
+        n->type_only_context = type_only_context;
 
         //  Remember current position, because we need to look ahead
         auto start_pos = pos;
@@ -7116,7 +7120,7 @@ class parser
                 }
 
                 //  Else try parsing it as a type id
-                else if (auto i = type_id(false, false, true)) {
+                else if (auto i = type_id(false, false, true, false)) {
                     term.arg = std::move(i);
                 }
 
@@ -7211,7 +7215,7 @@ class parser
 
         n->ids.push_back( std::move(term) );
 
-        for ( 
+        for (
             auto first_time_through_loop = true;
             curr().type() == lexeme::Scope;
             first_time_through_loop = false
@@ -7230,7 +7234,7 @@ class parser
                 && first_uid_was_std
                 && term.scope_op->type() == lexeme::Scope
                 && *term.id->identifier == "forward"
-                ) 
+                )
             {
                 error("std::forward is not needed in Cpp2 - use 'forward' parameters/arguments instead", false);
                 return {};
@@ -7887,7 +7891,7 @@ class parser
         }
 
         if (
-            peek(1) 
+            peek(1)
             && *peek(1) == "namespace"
             )
         {
diff --git a/source/to_cpp1.h b/source/to_cpp1.h
index 00ac1cdac..36a29f9e9 100644
--- a/source/to_cpp1.h
+++ b/source/to_cpp1.h
@@ -1255,7 +1255,7 @@ class cppfront
 
         //  Now we'll open the Cpp1 file
         auto cpp1_filename = sourcefile.substr(0, std::ssize(sourcefile) - 1);
-        
+
         //  Use explicit filename override if present,
         //  otherwise strip leading path
         if (!flag_cpp1_filename.empty()) {
@@ -1721,7 +1721,8 @@ class cppfront
         int                        synthesized_multi_return_size = 0,
         bool                       is_local_name                 = true,
         bool                       is_qualified                  = false,
-        bool                       is_class_member_access        = false
+        bool                       is_class_member_access        = false,
+        bool                       is_dependent                  = false
     )
         -> void
     {   STACKINSTR
@@ -1812,6 +1813,10 @@ class cppfront
             printer.print_cpp2("*this).", n.position());
         }
 
+        if (is_dependent && n.open_angle != source_position{}) {
+            printer.print_cpp2("template ", n.position());
+        }
+
         assert(n.identifier);
         emit(*n.identifier, is_qualified);  // inform the identifier if we know this is qualified
 
@@ -1878,11 +1883,271 @@ class cppfront
     }
 
 
+    auto has_template_parameter_named(declaration_node const& decl, token const& id)
+        -> bool
+    {
+        if (auto& params = decl.template_parameters) {
+            return std::any_of(params->parameters.begin(), params->parameters.end(), [&](auto& param) {
+                assert(param->has_name());
+                return *param->name() == id;
+            });
+        }
+        return false;
+    }
+
+    auto is_template_parameter(token const& lookup_id)
+        -> bool
+    {
+        // If any parent declaration
+        return std::any_of(current_declarations.begin() + 1, current_declarations.end(), [&](auto& decl) {
+            return has_template_parameter_named(*decl, lookup_id);
+        });
+    }
+
+    std::vector<token const*> looking_up = {};
+
+    auto is_dependent_type_alias(token const& lookup_id)
+        -> bool
+    {
+        // Prevent recursion.
+        if (contains(looking_up, &lookup_id)) {
+            return false;
+        }
+        looking_up.push_back(&lookup_id);
+        auto guard = finally([&]{ looking_up.pop_back(); });
+
+        auto lookup = source_order_name_lookup(lookup_id);
+
+        if (
+            !lookup
+            || get_if<active_using_declaration>(&*lookup)
+            )
+        {
+            return false;
+        }
+
+        auto decl = get<declaration_node const*>(*lookup);
+        if (!decl->is_alias()) {
+            return false;
+        }
+
+        auto& alias = get<declaration_node::an_alias>(decl->type);
+
+        if (
+            !alias->is_type_alias()
+            || !decl->identifier
+            || *decl->identifier->identifier != lookup_id
+            )
+        {
+            return false;
+        }
+
+        auto& type_id = get<alias_node::a_type>(alias->initializer);
+        return is_dependent(*type_id);
+    }
+
+    auto is_dependent(const type_id_node& n)
+        -> bool
+    {
+        if (auto qual = get_if<id_expression_node::qualified>(&n.id)) {
+            return is_dependent(**qual);
+        }
+        else if (auto unqual = get_if<id_expression_node::unqualified>(&n.id)) {
+            return is_dependent(**unqual);
+        }
+        return false;
+    }
+
+    auto is_dependent(const id_expression_node& n)
+        -> bool
+    {
+        if (auto qual = get_if<id_expression_node::qualified>(&n.id)) {
+            return is_dependent(**qual);
+        }
+        else if (auto unqual = get_if<id_expression_node::unqualified>(&n.id)) {
+            return is_dependent(**unqual);
+        }
+        return false;
+    }
+
+    struct is_dependent_expression_visitor {
+        cppfront* self;
+
+        auto operator()(expression_node const& expr) const
+            -> bool
+        {
+            return (*this)(*expr.expr);
+        }
+
+        template<String Name, typename Term>
+        auto operator()(binary_expression_node<Name, Term> const& expr) const
+            -> bool
+        {
+            return (*this)(*expr.expr) || std::any_of(expr.terms.begin(), expr.terms.end(), *this);
+        }
+
+        template<class BinaryExpressionTerm>
+        auto operator()(BinaryExpressionTerm const& term) const
+            -> bool
+            requires requires { term.op; term.expr; }
+        {
+            return (*this)(*term.expr);
+        }
+
+        auto operator()(is_as_expression_node const& expr) const
+            -> bool
+        {
+            return (*this)(*expr.expr) || std::any_of(expr.ops.begin(), expr.ops.end(), *this);
+        }
+
+        auto operator()(is_as_expression_node::term const& expr) const
+            -> bool
+        {
+            if (expr.expr) {
+                return (*this)(*expr.expr);
+            }
+            return self->is_dependent(*expr.type);
+        }
+
+        auto operator()(prefix_expression_node const& expr) const
+            -> bool
+        {
+            return (*this)(*expr.expr);
+        }
+
+        auto operator()(postfix_expression_node const& expr) const
+            -> bool
+        {
+            return (*this)(*expr.expr) || std::any_of(expr.ops.begin(), expr.ops.end(), *this);
+        }
+
+        auto operator()(postfix_expression_node::term const& expr) const
+            -> bool
+        {
+            if (expr.id_expr) {
+                return (*this)(*expr.id_expr);
+            } else if (expr.expr_list) {
+                return (*this)(*expr.expr_list);
+            }
+            return false;
+        }
+
+        auto operator()(primary_expression_node const& expr) const
+            -> bool
+        {
+            return std::visit([&]<typename T>(T const& expr) {
+                if constexpr (std::is_same_v<T, std::monostate>
+                              || std::is_same_v<T, token const*>
+                              || std::is_same_v<T, std::unique_ptr<literal_node>>) {
+                    return false;
+                } else {
+                    return (*this)(*expr);
+                }
+            }, expr.expr);
+        }
+
+        auto operator()(expression_list_node const& expr) const
+            -> bool
+        {
+            return std::any_of(expr.expressions.begin(), expr.expressions.end(), *this);
+        }
+
+        auto operator()(expression_list_node::term const& term) const
+            -> bool
+        {
+            return (*this)(*term.expr);
+        }
+
+        auto operator()(id_expression_node const& expr) const
+            -> bool
+        {
+            return std::visit([&]<typename T>(T const& expr) {
+                if constexpr (std::is_same_v<T, std::monostate>) {
+                    return false;
+                } else {
+                    return self->is_dependent(*expr);
+                }
+            }, expr.id);
+        }
+
+        auto operator()(declaration_node const& n) const
+            -> bool
+        {
+            auto type_id = std::get_if<declaration_node::an_object>(&n.type);
+            if (
+                !type_id
+                || (*type_id)->is_wildcard()
+                )
+            {
+                return false; // (*this)(*term.initializer);
+            }
+            return self->is_dependent(**type_id);
+        }
+
+        auto operator()(inspect_expression_node const& expr) const
+            -> bool
+        {
+            return self->is_dependent(*expr.result_type);
+        }
+    };
+
+    auto is_dependent(
+        const unqualified_id_node& n,
+        bool /*is_qualified*/ = false,
+        bool is_first = true)
+        -> bool
+    {
+        if (is_first && n.open_angle == source_position{}) {
+            assert(n.identifier);
+            return is_template_parameter(*n.identifier)
+                   || is_dependent_type_alias(*n.identifier);
+        }
+        // If it's a _template-id_
+        if (n.open_angle != source_position{}) {
+            assert(n.identifier);
+            // and any of its template arguments is either
+            return std::any_of(n.template_args.begin(), n.template_args.end(), [&](template_argument const& arg) {
+                if (auto expr = get_if<template_argument::expression>(&arg.arg)) {
+                    // a dependent _expression_
+                    return is_dependent_expression_visitor{this}(**expr);
+                }
+                else if (auto type_id = get_if<template_argument::type_id>(&arg.arg)) {
+                    // or a dependent _type-id_.
+                    return is_dependent(**type_id);
+                }
+                return false;
+            });
+        }
+        return false;
+    }
+
+    auto is_dependent(const qualified_id_node& n, bool exclude_last = false)
+        -> bool
+    {
+        if (is_dependent(*n.ids[0].id, true, true)) {
+            return true;
+        }
+        return std::any_of(
+                   n.ids.begin() + 1,
+                   n.ids.end() - int{exclude_last && n.ids.size() > 1},
+                   [&](auto& id) {
+                       return is_dependent(*id.id, true, false);
+                   }
+               );
+    }
+
+    auto should_be_prefixed_with_typename(const qualified_id_node& n)
+        -> bool
+    {
+        return is_dependent(n, true);
+    }
+
     //-----------------------------------------------------------------------
     //
     auto emit(
         qualified_id_node const& n,
-        bool include_unqualified_id = true
+        bool include_unqualified_id = true,
+        bool requires_typename_keyword = false
         )
         -> void
     {   STACKINSTR
@@ -1893,12 +2158,20 @@ class cppfront
         auto ident = std::string{};
         printer.emit_to_string(&ident);
 
+        if (requires_typename_keyword && should_be_prefixed_with_typename(n)) {
+            printer.print_cpp2("typename ", n.position());
+        }
+
+        auto is_dependent = false;
         for (auto const& id : std::span{n.ids}.first(n.ids.size() - !include_unqualified_id))
         {
             if (id.scope_op) {
                 emit(*id.scope_op);
             }
-            emit(*id.id, 0, true, true);    // inform the unqualified-id that it's qualified
+            emit(*id.id, 0, true, true, false, is_dependent);    // inform the unqualified-id that it's qualified
+            if (!is_dependent && this->is_dependent(*id.id)) {
+                is_dependent = true;
+            }
         }
 
         printer.emit_to_string();
@@ -1910,8 +2183,9 @@ class cppfront
     //
     auto emit(
         type_id_node const& n,
-        source_position     pos        = {},
-        std::string         identifier = {}
+        bool                in_cpp1_type_only_context = false,
+        source_position     pos                       = {},
+        std::string         identifier                = {}
     )
         -> void
     {   STACKINSTR
@@ -1940,7 +2214,7 @@ class cppfront
         }
         else {
             try_emit<type_id_node::unqualified>(n.id, 0, false);
-            try_emit<type_id_node::qualified  >(n.id);
+            try_emit<type_id_node::qualified  >(n.id, true, !in_cpp1_type_only_context && n.type_only_context);
             try_emit<type_id_node::keyword    >(n.id);
         }
 
@@ -3428,12 +3702,12 @@ class cppfront
                 last_was_prefixed = true;
             }
 
-            //  Handle the other Cpp2 postfix operators that stay postfix in Cpp1 
+            //  Handle the other Cpp2 postfix operators that stay postfix in Cpp1
             //  (currently '...' for expansion, not when used as a range operator)
             else if (
                 is_postfix_operator(i->op->type())
                 && !i->last_expr    // not being used as a range operator
-                ) 
+                )
             {
                 flush_args();
                 suffix.emplace_back( i->op->to_string(), i->op->position());
@@ -3474,7 +3748,7 @@ class cppfront
                     }
 
                     auto print = print_to_string(
-                        *i->id_expr, 
+                        *i->id_expr,
                         false, // not a local name
                         i->op->type() == lexeme::Dot || i->op->type() == lexeme::DotDot // member access
                     );
@@ -4356,6 +4630,84 @@ class cppfront
     }
 
 
+    auto is_deducible_template_parameter(token const& lookup_id)
+        -> bool
+    {
+        assert( current_declarations.back() );
+        return has_template_parameter_named(*current_declarations.back(), lookup_id)
+               || (
+                   current_declarations.back()->parent_is_type()
+                   && current_declarations.back()->has_name("operator=")
+                   && has_template_parameter_named(*current_declarations.back()->get_parent(), lookup_id)
+                  );
+    }
+
+    auto is_deducible(const type_id_node& n)
+        -> bool
+    {
+        if (auto qual = get_if<type_id_node::qualified>(&n.id)) {
+            return is_deducible(**qual);
+        }
+        else if (auto unqual = get_if<type_id_node::unqualified>(&n.id)) {
+            return is_deducible(**unqual);
+        }
+        return false;
+    }
+
+    auto is_deducible(const id_expression_node& n)
+        -> bool
+    {
+        if (auto qual = get_if<id_expression_node::qualified>(&n.id)) {
+            return is_deducible(**qual);
+        }
+        else if (auto unqual = get_if<id_expression_node::unqualified>(&n.id)) {
+            return is_deducible(**unqual);
+        }
+        return false;
+    }
+
+    auto is_deducible(
+        const unqualified_id_node& n,
+        bool is_first = true)
+        -> bool
+    {
+        // If it's not a _template-id_
+        if (is_first && n.open_angle == source_position{}) {
+            assert(n.identifier);
+            // and it names a deducible template parameter.
+            return is_deducible_template_parameter(*n.identifier);
+        }
+        // If it's a _template-id_
+        if (n.open_angle != source_position{}) {
+            assert(n.identifier);
+            // and any of its template arguments is either
+            return std::any_of(n.template_args.begin(), n.template_args.end(), [&](template_argument const& arg) {
+              if (auto expr = get_if<template_argument::expression>(&arg.arg);
+                  expr && (*expr)->is_id_expression()) {
+                  // a deducible _id-expression_
+                  auto& pid = (*expr)->expr->expr->expr->expr->expr->expr->expr->expr->expr->expr->expr->expr->expr->expr->expr->expr->expr;
+                  if (auto id = get_if<primary_expression_node::id_expression>(&pid)) {
+                      return is_deducible(**id);
+                  }
+              }
+              else if (auto type_id = get_if<template_argument::type_id>(&arg.arg)) {
+                  // or a deducible _type-id_.
+                  return is_deducible(**type_id);
+              }
+              return false;
+         });
+        }
+        return false;
+    }
+
+    auto is_deducible(const qualified_id_node& n)
+        -> bool
+    {
+        assert(n.ids.size() > 0);
+        // Its non-terminal components are non-dependent and
+        // its terminal component is deducible.
+        return !is_dependent(n, true) && is_deducible(*n.ids.back().id);
+    }
     //-----------------------------------------------------------------------
     //
     auto emit(
@@ -4406,8 +4758,8 @@ class cppfront
         {
             assert(n.declaration);
             auto is_param_to_namespace_scope_type =
-                n.declaration->parent_is_type() 
-                && n.declaration->parent_declaration->parent_is_namespace() 
+                n.declaration->parent_is_type()
+                && n.declaration->parent_declaration->parent_is_namespace()
                 ;
 
             auto emit_in_phase_0 =
@@ -4544,7 +4896,7 @@ class cppfront
         auto const& type_id = *std::get<declaration_node::an_object>(n.declaration->type);
 
         if (is_template_parameter) {
-            emit( type_id );
+            emit( type_id, true );
             printer.print_cpp2(" ", type_id.position());
 
             emit_template_name();
@@ -4556,52 +4908,14 @@ class cppfront
         //  Else handle ordinary parameters
 
         assert(n.declaration->identifier);
-        auto param_type = print_to_string(type_id, source_position{}, print_to_string(*n.declaration->identifier));
-
-        //  If there are template parameters on this function or its enclosing
-        //  type, see if this parameter's name is an unqualified-id with a
-        //  template parameter name, or mentions a template parameter as a
-        //  template argument
-        auto has_template_parameter_type_named = [](
-            declaration_node const& decl,
-            std::string_view        name
-            )
-            -> bool
-        {
-            if (decl.template_parameters) {
-                for (auto& tparam : decl.template_parameters->parameters)
-                {
-                    assert(
-                        tparam
-                        && tparam->name()
-                    );
-                    //  For now just do a quick string match
-                    auto tparam_name = tparam->name()->to_string();
-                    if (
-                        tparam->declaration->is_type()
-                        && (
-                            name == tparam_name
-                            || name.find("<"+tparam_name) != name.npos
-                            || name.find(","+tparam_name) != name.npos
-                        )
-                        )
-                    {
-                        return true;
-                    }
-                }
-            }
-            return false;
-        };
+        auto param_type = print_to_string(
+            type_id,
+            n.pass != passing_style::in,
+            source_position{},
+            print_to_string(*n.declaration->identifier)
+        );
 
-        assert( current_declarations.back() );
-        auto is_dependent_parameter_type =
-            has_template_parameter_type_named( *current_declarations.back(), param_type )
-            || (
-                current_declarations.back()->parent_is_type()
-                && current_declarations.back()->has_name("operator=")
-                && has_template_parameter_type_named( *current_declarations.back()->get_parent(), param_type)
-                )
-            ;
+        auto is_deducible_parameter_type = is_deducible(type_id);
 
         //  First any prefix
 
@@ -4614,7 +4928,7 @@ class cppfront
             !is_returns
             && !n.declaration->is_variadic
             && !type_id.is_wildcard()
-            && !is_dependent_parameter_type
+            && !is_deducible_parameter_type
             && !type_id.is_pointer_qualified()
             )
         {
@@ -4636,12 +4950,12 @@ class cppfront
         }
         else if (
             type_id.is_wildcard()
-            || is_dependent_parameter_type
+            || is_deducible_parameter_type
             || n.declaration->is_variadic
             )
         {
             auto name = std::string{"auto"};
-            if (is_dependent_parameter_type) {
+            if (is_deducible_parameter_type) {
                 name = param_type;
             }
             else if (
@@ -4691,6 +5005,11 @@ class cppfront
             auto req = std::string{"std::is_convertible_v<CPP2_TYPEOF("};
             req += identifier;
             req += "), std::add_const_t<";
+            // The call to 'print_to_string' just computed this.
+            // We could cache that so it's reused here.
+            if (is_dependent(type_id)) {
+                req += "typename ";
+            }
             req += param_type;
             req += ">&>";
             function_requires_conditions.push_back(req);
@@ -4711,7 +5030,7 @@ class cppfront
         if (
             !is_returns
             && !type_id.is_wildcard()
-            && !is_dependent_parameter_type
+            && !is_deducible_parameter_type
             && !type_id.is_pointer_qualified()
             && !n.declaration->is_variadic
             )
@@ -4952,7 +5271,7 @@ class cppfront
             auto& r = std::get<function_type_node::id>(n.returns);
             assert(r.type);
 
-            auto return_type = print_to_string(*r.type);
+            auto return_type = print_to_string(*r.type, true);
 
             if (r.pass == passing_style::forward) {
                 if (r.type->is_wildcard()) {
@@ -5033,7 +5352,7 @@ class cppfront
             || n.is_swap()
             || n.is_destructor()
             || (
-                n.my_decl 
+                n.my_decl
                 && generating_move_from == n.my_decl
                 )
             )
@@ -5047,7 +5366,7 @@ class cppfront
         if (
             n.is_assignment()
             || (
-                n.my_decl 
+                n.my_decl
                 && generating_assignment_from == n.my_decl
                 )
             )
@@ -5514,6 +5833,9 @@ class cppfront
                             + (*object)->name()->to_string()
                             + "_as_base";
                     }
+                    else if (object_name.starts_with("typename ")) {
+                        object_name = std::string_view{object_name.begin() + 9, object_name.end()};
+                    }
 
                     //  Flush any 'out' parameter initializations
                     auto out_inits_with_commas = [&]() -> std::string {
@@ -5784,7 +6106,7 @@ class cppfront
                         "using "
                             + print_to_string(*n.identifier)
                             + " = "
-                            + print_to_string( *std::get<alias_node::a_type>(a->initializer) )
+                            + print_to_string( *std::get<alias_node::a_type>(a->initializer), true )
                             + ";\n",
                         n.position()
                     );
@@ -6201,7 +6523,7 @@ class cppfront
                     if (decl->has_name("this")) {
                         if (printer.get_phase() == printer.phase1_type_defs_func_decls) {
                             printer.print_cpp2(
-                                separator + " public " + print_to_string(*decl->get_object_type()),
+                                separator + " public " + print_to_string(*decl->get_object_type(), true),
                                 compound_stmt->position()
                             );
                             separator = ",";
@@ -6915,10 +7237,10 @@ class cppfront
                 assert(n.initializer);
                 //  And the constraint if there is one
                 if (type->constraint) {
-                    emit( *type->constraint, n.position() );
+                    emit( *type->constraint, false, n.position() );
                     printer.print_cpp2(" ", n.position());
                 }
-                emit( *type, n.position() );
+                emit( *type, false, n.position() );
             }
             //  Otherwise, emit the type
             else {
@@ -6935,8 +7257,8 @@ class cppfront
                         return;
                     }
                 }
-                printer.preempt_position_push(n.position()); 
-                emit( *type, {}, print_to_string(*n.identifier) ); 
+                printer.preempt_position_push(n.position());
+                emit( *type, n.parent_is_type(), {}, print_to_string(*n.identifier) );
                 printer.preempt_position_pop();
 
                 if (