fix(to_cpp1): consider that postfix tem can be empty

Author: JohelEGP

regression-tests/pure2-bugfix-for-dependent-types.cpp2

@@ -88,4 +88,6 @@ main: () = {
       _ = :alias::value_type = 0; // Non-dependent.
     }
   }(0);
+
+  _ = :(r) -> std::type_identity_t<decltype(begin(r)*)> = r[0];(std::vector<int>(1));
 }

regression-tests/test-results/gcc-13/gcc-version.output

@@ -1,4 +1,4 @@
-gcc (GCC) 13.2.1 20231011 (Red Hat 13.2.1-4)
+c++ (GCC) 13.2.1 20230801
 Copyright (C) 2023 Free Software Foundation, Inc.
 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

regression-tests/test-results/gcc-13/pure2-bugfix-for-dependent-types-recursion.cpp.output

@@ -1,13 +1,13 @@
-pure2-bugfix-for-dependent-types-recursion.cpp: In function ‘int main()’:
-pure2-bugfix-for-dependent-types-recursion.cpp:19:13: error: ‘b’ does not name a type
-   19 |   using a = b;
+pure2-bugfix-for-dependent-types-recursion.cpp2: In function ‘int main()’:
+pure2-bugfix-for-dependent-types-recursion.cpp2:2:13: error: ‘b’ does not name a type
+    2 |   a: type == b;
       |             ^
-pure2-bugfix-for-dependent-types-recursion.cpp:20:13: error: ‘a’ does not name a type
-   20 |   using b = a;
+pure2-bugfix-for-dependent-types-recursion.cpp2:3:13: error: ‘a’ does not name a type
+    3 |   b: type == a;
       |             ^
-pure2-bugfix-for-dependent-types-recursion.cpp:21:21: error: ‘a’ has not been declared
-   21 |   static_cast<void>(a::t);
+pure2-bugfix-for-dependent-types-recursion.cpp2:4:21: error: ‘a’ has not been declared
+    4 |   _ = a::t;
       |                     ^
-pure2-bugfix-for-dependent-types-recursion.cpp:22:21: error: ‘b’ has not been declared
-   22 |   static_cast<void>(b::t);
+pure2-bugfix-for-dependent-types-recursion.cpp2:5:21: error: ‘b’ has not been declared
+    5 |   _ = b::t;
       |                     ^

regression-tests/test-results/pure2-bugfix-for-dependent-types.cpp

@@ -120,5 +120,7 @@ auto main() -> int{
       static_cast<void>(typename alias::value_type{0});// Non-dependent.
     }
   }(0));
+
+  static_cast<void>([](auto const& r) -> std::type_identity_t<decltype(*cpp2::assert_not_null(begin(r)))> { return CPP2_ASSERT_IN_BOUNDS(r, 0);  }(std::vector<int>(1)));
 }
 

source/to_cpp1.h

@@ -1947,8 +1947,10 @@ class cppfront
         {
             if (expr.id_expr) {
                 return (*this)(*expr.id_expr);
+            } else if (expr.expr_list) {
+                return (*this)(*expr.expr_list);
             }
-            return (*this)(*expr.expr_list);
+            return false;
         }
 
         auto operator()(primary_expression_node const& expr) const