Add printing for (multiple, flag, values)

And add support for reflecting aliases (though I ended up not using it in the final version this commit)

Author: hsutter

include/cpp2util.h

@@ -1599,6 +1599,8 @@ class strict_value {
     auto operator& ( strict_value const& that ) const -> strict_value requires BitwiseOps { return strict_value(t & that.t); }
     auto operator^ ( strict_value const& that ) const -> strict_value requires BitwiseOps { return strict_value(t ^ that.t); }
 
+    auto has       ( strict_value const& that ) const -> bool         requires BitwiseOps { return t & that.t; }
+
     auto set       ( strict_value const& that )       -> void         requires BitwiseOps { t |=  that.t; }
     auto clear     ( strict_value const& that )       -> void         requires BitwiseOps { t &= ~that.t; }
 };

regression-tests/pure2-enum.cpp2

@@ -77,6 +77,8 @@ main: () = {
     f  |= file_attributes::obsolete;
     f2 |= file_attributes::current;
 
+    std::cout << "f  is " << f  << "\n";
+    std::cout << "f2 is " << f2 << "\n";
     std::cout << "f  as int  is (f  as int )$\n";
     std::cout << "f2 as int  is (f2 as int )$\n";
     std::cout << "f  == f2   is (f  == f2  )$\n";

regression-tests/test-results/clang-12/pure2-enum.cpp.execution

@@ -8,6 +8,8 @@ f2 as int  is 1
 f  is (f2) is 1
 f2 is (f ) is 1
 
+f  is (cached, current, obsolete)
+f2 is (cached, current)
 f  as int  is 7
 f2 as int  is 3
 f  == f2   is 0

regression-tests/test-results/gcc-10/pure2-bugfix-for-requires-clause-in-forward-declaration.cpp.output

@@ -1,21 +1,32 @@
-pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:3:36: error: expected ‘;’ at end of member declaration
+pure2-bugfix-for-requires-clause-in-forward-declaration.cpp:16:36: error: expected ‘;’ at end of member declaration
+   16 |   public: explicit element(auto&& n)
+      |                                    ^
+      |                                     ;
 In file included from pure2-bugfix-for-requires-clause-in-forward-declaration.cpp:7:
-../../../include/cpp2util.h:1802:47: error: static assertion failed: GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.
- 1802 |     #define CPP2_REQUIRES_(...) static_assert(false, "GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.")
+../../../include/cpp2util.h:1804:47: error: static assertion failed: GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.
+ 1804 |     #define CPP2_REQUIRES_(...) static_assert(false, "GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.")
       |                                               ^~~~~
-pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:4:1: note: in expansion of macro ‘CPP2_REQUIRES_’
+pure2-bugfix-for-requires-clause-in-forward-declaration.cpp:17:1: note: in expansion of macro ‘CPP2_REQUIRES_’
+   17 | CPP2_REQUIRES_ (std::is_same_v<CPP2_TYPEOF(n), std::string>)
+      | ^~~~~~~~~~~~~~
 pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:3:46: error: expected ‘;’ at end of member declaration
 In file included from pure2-bugfix-for-requires-clause-in-forward-declaration.cpp:7:
-../../../include/cpp2util.h:1802:47: error: static assertion failed: GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.
- 1802 |     #define CPP2_REQUIRES_(...) static_assert(false, "GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.")
+../../../include/cpp2util.h:1804:47: error: static assertion failed: GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.
+ 1804 |     #define CPP2_REQUIRES_(...) static_assert(false, "GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.")
       |                                               ^~~~~
 pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:4:1: note: in expansion of macro ‘CPP2_REQUIRES_’
 pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:3:3: error: no declaration matches ‘element::element(auto:80&&) requires  is_same_v<typename std::remove_cv<typename std::remove_reference<decltype(element::__ct ::n)>::type>::type, std::__cxx11::string>’
 pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:5:11: note: candidates are: ‘element::element(const element&)’
-pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:3:20: note:                 ‘template<class auto:78> element::element(auto:78&&)’
-pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:1:7: note: ‘class element’ defined here
+pure2-bugfix-for-requires-clause-in-forward-declaration.cpp:16:20: note:                 ‘template<class auto:78> element::element(auto:78&&)’
+   16 |   public: explicit element(auto&& n)
+      |                    ^~~~~~~
+pure2-bugfix-for-requires-clause-in-forward-declaration.cpp:14:7: note: ‘class element’ defined here
+   14 | class element {
+      |       ^~~~~~~
 pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:3:3: error: expected unqualified-id before ‘{’ token
 pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:3:8: error: no declaration matches ‘element& element::operator=(auto:81&&) requires  is_same_v<typename std::remove_cv<typename std::remove_reference<decltype(element::operator=::n)>::type>::type, std::__cxx11::string>’
 pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:6:16: note: candidates are: ‘void element::operator=(const element&)’
 pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:3:16: note:                 ‘template<class auto:79> element& element::operator=(auto:79&&)’
-pure2-bugfix-for-requires-clause-in-forward-declaration.cpp2:1:7: note: ‘class element’ defined here
+pure2-bugfix-for-requires-clause-in-forward-declaration.cpp:14:7: note: ‘class element’ defined here
+   14 | class element {
+      |       ^~~~~~~

regression-tests/test-results/gcc-10/pure2-enum.cpp.execution

@@ -8,6 +8,8 @@ f2 as int  is 1
 f  is (f2) is 1
 f2 is (f ) is 1
 
+f  is (cached, current, obsolete)
+f2 is (cached, current)
 f  as int  is 7
 f2 as int  is 3
 f  == f2   is 0

regression-tests/test-results/gcc-10/pure2-requires-clauses.cpp.output

@@ -1,5 +1,5 @@
 In file included from pure2-requires-clauses.cpp:7:
-../../../include/cpp2util.h:1802:33: error: expected unqualified-id before ‘static_assert’
- 1802 |     #define CPP2_REQUIRES_(...) static_assert(false, "GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.")
+../../../include/cpp2util.h:1804:33: error: expected unqualified-id before ‘static_assert’
+ 1804 |     #define CPP2_REQUIRES_(...) static_assert(false, "GCC 11 or higher is required to support variables and type-scope functions that have a 'requires' clause. This includes a type-scope 'forward' parameter of non-wildcard type, such as 'func: (this, forward s: std::string)', which relies on being able to add a 'requires' clause - in that case, use 'forward s: _' instead if you need the result to compile with GCC 10.")
       |                                 ^~~~~~~~~~~~~
 pure2-requires-clauses.cpp2:19:1: note: in expansion of macro ‘CPP2_REQUIRES_’

regression-tests/test-results/gcc-13/pure2-enum.cpp.execution

@@ -8,6 +8,8 @@ f2 as int  is 1
 f  is (f2) is 1
 f2 is (f ) is 1
 
+f  is (cached, current, obsolete)
+f2 is (cached, current)
 f  as int  is 7
 f2 as int  is 3
 f  == f2   is 0

regression-tests/test-results/mixed-bugfix-for-cpp2-comment-cpp1-sequence.cpp

@@ -9,13 +9,11 @@
 
 //=== Cpp2 type definitions and function declarations ===========================
 
-#line 1 "mixed-bugfix-for-cpp2-comment-cpp1-sequence.cpp2"
 extern cpp2::i32 x;
 int main() { }
             // ugh
 
 //=== Cpp2 function definitions =================================================
 
-#line 1 "mixed-bugfix-for-cpp2-comment-cpp1-sequence.cpp2"
 cpp2::i32 x {0}; 
 

regression-tests/test-results/msvc-2022/pure2-enum.cpp.execution

@@ -8,6 +8,8 @@ f2 as int  is 1
 f  is (f2) is 1
 f2 is (f ) is 1
 
+f  is (cached, current, obsolete)
+f2 is (cached, current)
 f  as int  is 7
 f2 as int  is 3
 f  == f2   is 0

regression-tests/test-results/pure2-bounds-safety-span.cpp

@@ -18,7 +18,6 @@
 auto print_and_decorate(auto const& thing) -> void;
 
 
-#line 1 "pure2-bounds-safety-span.cpp2"
 
 //=== Cpp2 function definitions =================================================