fix(parse): permit unbraced function expression as template argument

Author: JohelEGP

regression-tests/test-results/pure2-bugfix-for-unbraced-function-expression.cpp

@@ -1,20 +1,18 @@
 
-#define CPP2_USE_MODULES         Yes
+#define CPP2_IMPORT_STD          Yes
 
 //=== Cpp2 type declarations ====================================================
 
 
 #include "cpp2util.h"
 
-#line 1 "pure2-bugfix-for-unbraced-function-expression.cpp2"
 class t;
 
 
 //=== Cpp2 type definitions and function declarations ===========================
 
-#line 1 "pure2-bugfix-for-unbraced-function-expression.cpp2"
 class t {
-  public: auto operator[](auto const& f) const -> void;
+  public: auto operator[](auto const& f) const& -> void;
 
   public: t() = default;
   public: t(t const&) = delete; /* No 'that' constructor, suppress copy */
@@ -28,7 +26,7 @@ class t {
 
 
 #line 2 "pure2-bugfix-for-unbraced-function-expression.cpp2"
-  auto t::operator[](auto const& f) const -> void{}
+  auto t::operator[](auto const& f) const& -> void{}
 
 [[nodiscard]] auto main() -> int{
 {

source/parse.h

@@ -5364,6 +5364,7 @@ class parser
                     && curr().type() != lexeme::LeftParen               // not imediatelly called
                     && curr().type() != lexeme::RightParen              // not as a last argument to function
                     && curr().type() != lexeme::Comma                   // not as first or in-the-middle, function argument
+                    && curr().type() != lexeme::Greater                 // not as the last argument to template
                     && curr().type() != lexeme::RightBracket            // not as the last index argument
                     && curr() != "is"                                   // not as the argument to is
                     && curr() != "as"                                   // not as the argument to as