fix(parse): recognize const and pointer template arguments

regression-tests/pure2-bugfix-for-template-argument.cpp2

@@ -0,0 +1,3 @@
+main: () = //
+  std::is_void_v<* i32> //
+  && std::is_void_v<const i32>;

regression-tests/test-results/pure2-bugfix-for-template-argument.cpp

@@ -0,0 +1,23 @@
+
+#define CPP2_USE_MODULES         Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-bugfix-for-template-argument.cpp2"
+auto main() -> int;
+
+
+//=== Cpp2 function definitions =================================================
+
+#line 1 "pure2-bugfix-for-template-argument.cpp2"
+auto main() -> int { //
+  std::is_void_v<cpp2::i32*> //
+  && std::is_void_v<cpp2::i32 const>; }
+

regression-tests/test-results/pure2-bugfix-for-template-argument.cpp2.output

@@ -0,0 +1,2 @@
+pure2-bugfix-for-template-argument.cpp2... ok (all Cpp2, passes safety checks)
+

source/parse.h

@@ -721,7 +721,7 @@ struct postfix_expression_node
         if (ops.empty()) {
             return false;
         } else {
-            return (ops.front().op->type() == lexeme::Ampersand 
+            return (ops.front().op->type() == lexeme::Ampersand
                     || ops.front().op->type() == lexeme::Tilde);
         }
     }
@@ -3965,7 +3965,7 @@ class parser
             //      || curr().type() == lexeme::LeftBrace
             )
         {
-            bool inside_initializer = ( 
+            bool inside_initializer = (
                 peek(-1) && peek(-1)->type() == lexeme::Assignment
             );
             auto open_paren = &curr();
@@ -3987,12 +3987,12 @@ class parser
             next();
             if (
                    curr().type() != lexeme::Semicolon
-                && curr().type() != lexeme::RightParen 
-                && curr().type() != lexeme::RightBracket 
+                && curr().type() != lexeme::RightParen
+                && curr().type() != lexeme::RightBracket
                 && curr().type() != lexeme::Comma
             ) {
                 expr_list->inside_initializer = false;
-            } 
+            }
             n->expr = std::move(expr_list);
             return n;
         }
@@ -4350,7 +4350,7 @@ class parser
     //G     shift-expression '<<' additive-expression
     //G     shift-expression '>>' additive-expression
     //G
-    auto shift_expression(bool allow_angle_operators = true) 
+    auto shift_expression(bool allow_angle_operators = true)
         -> auto
     {
         if (allow_angle_operators) {
@@ -4385,7 +4385,7 @@ class parser
     //G     shift-expression
     //G     compare-expression '<=>' shift-expression
     //G
-    auto compare_expression(bool allow_angle_operators = true) 
+    auto compare_expression(bool allow_angle_operators = true)
         -> auto
     {
         return binary_expression<compare_expression_node> (
@@ -4401,7 +4401,7 @@ class parser
     //G     relational-expression '<=' compare-expression
     //G     relational-expression '>=' compare-expression
     //G
-    auto relational_expression(bool allow_angle_operators = true) 
+    auto relational_expression(bool allow_angle_operators = true)
         -> auto
     {
         if (allow_angle_operators) {
@@ -4433,7 +4433,7 @@ class parser
     //G     equality-expression '==' relational-expression
     //G     equality-expression '!=' relational-expression
     //G
-    auto equality_expression(bool allow_angle_operators = true) 
+    auto equality_expression(bool allow_angle_operators = true)
         -> auto
     {
         return binary_expression<equality_expression_node> (
@@ -4446,7 +4446,7 @@ class parser
     //G     equality-expression
     //G     bit-and-expression '&' equality-expression
     //G
-    auto bit_and_expression(bool allow_angle_operators = true) 
+    auto bit_and_expression(bool allow_angle_operators = true)
         -> auto
     {
         return binary_expression<bit_and_expression_node> (
@@ -4459,7 +4459,7 @@ class parser
     //G     bit-and-expression
     //G     bit-xor-expression '^' bit-and-expression
     //G
-    auto bit_xor_expression(bool allow_angle_operators = true) 
+    auto bit_xor_expression(bool allow_angle_operators = true)
         -> auto
     {
         return binary_expression<bit_xor_expression_node> (
@@ -4472,7 +4472,7 @@ class parser
     //G     bit-xor-expression
     //G     bit-or-expression '|' bit-xor-expression
     //G
-    auto bit_or_expression(bool allow_angle_operators = true) 
+    auto bit_or_expression(bool allow_angle_operators = true)
         -> auto
     {
         return binary_expression<bit_or_expression_node> (
@@ -4485,7 +4485,7 @@ class parser
     //G     bit-or-expression
     //G     logical-and-expression '&&' bit-or-expression
     //G
-    auto logical_and_expression(bool allow_angle_operators = true) 
+    auto logical_and_expression(bool allow_angle_operators = true)
         -> auto
     {
         return binary_expression<logical_and_expression_node> (
@@ -4500,7 +4500,7 @@ class parser
     //G     logical-and-expression
     //G     logical-or-expression '||' logical-and-expression
     //G
-    auto logical_or_expression(bool allow_angle_operators = true) 
+    auto logical_or_expression(bool allow_angle_operators = true)
         -> auto
     {
         return binary_expression<logical_or_expression_node> (
@@ -4789,6 +4789,7 @@ class parser
     //G
     //G template-argument:
     //G     # note: < > << >> are not allowed in expressions until new ( is opened
+    //G     const type-id
     //G     expression
     //G     type-id
     //G
@@ -4818,12 +4819,22 @@ class parser
 
             n->open_angle = curr().position();
             next();
-            
+
             auto term = unqualified_id_node::term{};
 
             do {
-                // disallow unparenthesized relational comparisons in template args
-                if (auto e = expression(false)) {
+                if (auto e = [&]() {
+                    // If the template-argument can only be a type id
+                    // skip the expression production, because it start with
+                    if (
+                      curr().type() == lexeme::Multiply // '*'
+                      || curr() == "const"              // 'const'
+                    ) {
+                        return decltype(expression()){};
+                    }
+                    // disallow unparenthesized relational comparisons in template args
+                    return expression(false);
+                    }()) {
                     term.arg = std::move(e);
                 }
                 else if (auto i = type_id()) {
@@ -6389,7 +6400,7 @@ class parser
             }
             assert (n->is_type());
         }
-        
+
         //  Or a function type, declaring a function - and tell the function whether it's in a user-defined type
         else if (auto t = function_type(n.get(), named))
         {
@@ -6537,11 +6548,11 @@ class parser
                 )
             {
                 auto& type = std::get<declaration_node::an_object>(n->type);
-                // object initialized by the address of the curr() object 
+                // object initialized by the address of the curr() object
                 if (peek(1)->type() == lexeme::Ampersand) {
                     type->address_of = &curr();
                 }
-                // object initialized by (potentially multiple) dereference of the curr() object 
+                // object initialized by (potentially multiple) dereference of the curr() object
                 else if (peek(1)->type() == lexeme::Multiply) {
                     type->dereference_of = &curr();
                     for (int i = 1; peek(i)->type() == lexeme::Multiply; ++i)
@@ -6746,7 +6757,7 @@ class parser
                 return {};
             }
             if (
-                t->is_wildcard() 
+                t->is_wildcard()
                 || ( t->get_token() && t->get_token()->to_string(true) == "auto" )
             ) {
                 errors.emplace_back(