gdb/testsuite/gdb.cp/rvalue-ref-overload.cc

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 1998-2020 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 /* Rvalue references overload tests for GDB, based on overload.cc.  */
  19
  20 #include <stddef.h>
  21 #include <utility>
  22
  23 class foo;
  24
  25 typedef foo &foo_lval_ref;
  26 typedef foo &&foo_rval_ref;
  27
  28 class foo
  29 {
  30 public:
  31   foo ();
  32   foo (foo_lval_ref);
  33   foo (foo_rval_ref);
  34   ~foo ();
  35
  36   int overload1arg (foo_lval_ref);
  37   int overload1arg (foo_rval_ref);
  38   int overloadConst (const foo &);
  39   int overloadConst (const foo &&);
  40 };
  41
  42 void
  43 marker1 ()
  44 {
  45 }
  46
  47 static int
  48 f (int &x)
  49 {
  50   return 1;
  51 }
  52
  53 static int
  54 f (const int &x)
  55 {
  56   return 2;
  57 }
  58
  59 static int
  60 f (int &&x)
  61 {
  62   return 3;
  63 }
  64
  65 static int
  66 g (int &&x)
  67 {
  68   return x;
  69 }
  70
  71 int
  72 main ()
  73 {
  74   foo foo_rr_instance1;
  75   foo arg;
  76   int i = 0;
  77   const int ci = 0;
  78
  79   // result = 1 + 2 + 3 + 3 = 9
  80   int result = f (i) + f (ci) + f (0) + f (std::move (i));
  81
  82   /* Overload resolution below requires both a CV-conversion
  83      and reference conversion.  */
  84   int test_const // = 3
  85     = foo_rr_instance1.overloadConst (arg);
  86
  87   /* The statement below is illegal: cannot bind rvalue reference of
  88      type 'int&&' to lvalue of type 'int'.
  89
  90      result = g (i); */
  91   result = g (5); // this is OK
  92
  93   marker1 (); // marker1-returns-here
  94   return result;
  95 }
  96
  97 foo::foo  ()                       {}
  98 foo::foo  (foo_lval_ref afoo)      {}
  99 foo::foo  (foo_rval_ref afoo)      {}
 100 foo::~foo ()                       {}
 101
 102 /* Some functions to test overloading by varying one argument type. */
 103
 104 int foo::overload1arg (foo_lval_ref arg)           { return 1; }
 105 int foo::overload1arg (foo_rval_ref arg)           { return 2; }
 106 int foo::overloadConst (const foo &arg)            { return 3; }
 107 int foo::overloadConst (const foo &&arg)           { return 4; }