Fix cpp2::move

I don't recall why we had the more complex design of "move only from copyable types"... rvalues can be of any type, so the extra overload for noncopyable types isn't needed

This change highlighted that a handful of tests in pure2-last-use.cpp2 were incorrect, fixing those too

Author: hsutter

include/cpp2util.h

@@ -672,17 +672,10 @@ concept valid_custom_is_operator = predicate_member_fun<X, F, &F::op_is>
 //
 
 template <typename T>
-    requires (std::is_copy_constructible_v<std::remove_cvref_t<T>>)
 inline constexpr auto move(T&& t) -> decltype(auto) {
     return std::move(t);
 }
 
-template <typename T>
-    requires (!std::is_copy_constructible_v<std::remove_cvref_t<T>>)
-inline constexpr auto move(T&& t) -> decltype(auto) {
-    return std::forward<T>(t);
-}
-
 inline constexpr auto max(auto... values) {
     return std::max( { values... } );
 }

regression-tests/pure2-last-use.cpp2

@@ -136,12 +136,12 @@ issue_847_0: (copy v: std::vector<std::unique_ptr<int>>) = {
   do (_) {
   }
 }
-issue_847_1: (move v: std::vector<std::unique_ptr<int>>) = {
-  for v.make_copy()
-  do (move x) {
-    f_inout(x);
-  }
-}
+// issue_847_1: (move v: std::vector<std::unique_ptr<int>>) = {
+//   for v.make_copy()
+//   do (move x) {
+//     f_inout(x);  // error, can't pass rvalue to inout param
+//   }
+// }
 issue_847_5: (forward v) = {
   for v.make_copy()
   do (forward x) {
@@ -170,10 +170,10 @@ issue_857: type = {
   a: std::unique_ptr<int>;
   b: std::unique_ptr<int>;
   operator=: (out this, move that) = { }
-  operator=: (move this) = {
-    f_inout(a);
-    f_inout(this.b);
-  }
+//   operator=: (move this) = {
+//     f_inout(a);      // error, can't pass rvalue to inout param
+//     f_inout(this.b); // error, can't pass rvalue to inout param
+//   }
   //f: (move this) = f_copy(this);
   //f: (move this, move that) = f_copy(this, that);
   //g: (move this) = f_copy(this.a);
@@ -363,7 +363,7 @@ issue_857_9: @struct type = {
 //f3: (move this) = d();
 
   // OK: Explicit 'this' for base members, like in templates.
-  g0: (move this) = f_inout(this.a);
+  //g0: (move this) = f_inout(this.a);  // error, can't pass rvalue to inout param
   //g1: (move this) = _ = this.b();
   g2: (move this) = f_inout(this.c);
   //g3: (move this) = this.d();
@@ -806,6 +806,7 @@ enum_0: () = {
 enum_1: () = {
     max_value := new<int>(0);
     min_value: std::reference_wrapper<const std::unique_ptr<int>> = max_value;
+    _ = max_value;
 
     // for  (0)
     // do   (copy x)
@@ -947,7 +948,7 @@ g: () = {
   _ = :() = {
     x := new<int>(0);
     f_inout(x);
-    // _ = :() -> int = (:() x$*)$();
+    _ = :() -> int = (:() x$*)$();
   };
 }
 

regression-tests/test-results/clang-12-c++20/pure2-last-use.cpp.output

@@ -1,4 +1,4 @@
-pure2-last-use.cpp2:944:44: error: a lambda expression cannot appear in this context
+pure2-last-use.cpp2:945:44: error: a lambda expression cannot appear in this context
     static_cast<void>([_0 = std::array<int,[](auto const& x) mutable -> auto { return identity(x); }(0)>()]() mutable -> auto { return _0;  });// Fails on Clang 12 (lambda in unevaluated context).
                                            ^
 1 error generated.

regression-tests/test-results/gcc-14-c++2b/mixed-bugfix-for-ufcs-non-local.cpp.output

@@ -1,41 +1,41 @@
 In file included from mixed-bugfix-for-ufcs-non-local.cpp:6:
 ../../../include/cpp2util.h:2100:1: error: lambda-expression in template parameter type
- 2100 | //
+ 2100 | //-------------------------------------------------------------------------------------------------------------
       | ^
 ../../../include/cpp2util.h:2137:59: note: in expansion of macro ‘CPP2_UFCS_’
- 2137 |     //  Value case
+ 2137 | 
       |                                                           ^         
 mixed-bugfix-for-ufcs-non-local.cpp2:13:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:13:36: error: template argument 1 is invalid
 ../../../include/cpp2util.h:2100:1: error: lambda-expression in template parameter type
- 2100 | //
+ 2100 | //-------------------------------------------------------------------------------------------------------------
       | ^
 ../../../include/cpp2util.h:2137:59: note: in expansion of macro ‘CPP2_UFCS_’
- 2137 |     //  Value case
+ 2137 | 
       |                                                           ^         
 mixed-bugfix-for-ufcs-non-local.cpp2:21:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:21:36: error: template argument 1 is invalid
 ../../../include/cpp2util.h:2100:1: error: lambda-expression in template parameter type
- 2100 | //
+ 2100 | //-------------------------------------------------------------------------------------------------------------
       | ^
 ../../../include/cpp2util.h:2137:59: note: in expansion of macro ‘CPP2_UFCS_’
- 2137 |     //  Value case
+ 2137 | 
       |                                                           ^         
 mixed-bugfix-for-ufcs-non-local.cpp2:31:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:31:36: error: template argument 1 is invalid
 ../../../include/cpp2util.h:2100:1: error: lambda-expression in template parameter type
- 2100 | //
+ 2100 | //-------------------------------------------------------------------------------------------------------------
       | ^
 ../../../include/cpp2util.h:2137:59: note: in expansion of macro ‘CPP2_UFCS_’
- 2137 |     //  Value case
+ 2137 | 
       |                                                           ^         
 mixed-bugfix-for-ufcs-non-local.cpp2:33:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:33:36: error: template argument 1 is invalid
 ../../../include/cpp2util.h:2100:1: error: lambda-expression in template parameter type
- 2100 | //
+ 2100 | //-------------------------------------------------------------------------------------------------------------
       | ^
 ../../../include/cpp2util.h:2137:59: note: in expansion of macro ‘CPP2_UFCS_’
- 2137 |     //  Value case
+ 2137 | 
       |                                                           ^         
 mixed-bugfix-for-ufcs-non-local.cpp2:21:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:21:36: error: template argument 1 is invalid