assert/tst-assert-c++.cc

   1 /* Tests for interactions between C++ and assert.
   2    Copyright (C) 2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20
  21 /* The C++ standard requires that if the assert argument is a constant
  22    subexpression, then the assert itself is one, too.  */
  23 constexpr int
  24 check_constexpr ()
  25 {
  26   return (assert (true), 1);
  27 }
  28
  29 /* Objects of this class can be contextually converted to bool, but
  30    cannot be compared to int.  */
  31 struct no_int
  32 {
  33   no_int () = default;
  34   no_int (const no_int &) = delete;
  35
  36   explicit operator bool () const
  37   {
  38     return true;
  39   }
  40
  41   bool operator! () const; /* No definition.  */
  42   template <class T> bool operator== (T) const; /* No definition.  */
  43   template <class T> bool operator!= (T) const; /* No definition.  */
  44 };
  45
  46 /* This class tests that operator== is not used by assert.  */
  47 struct bool_and_int
  48 {
  49   bool_and_int () = default;
  50   bool_and_int (const no_int &) = delete;
  51
  52   explicit operator bool () const
  53   {
  54     return true;
  55   }
  56
  57   bool operator! () const; /* No definition.  */
  58   template <class T> bool operator== (T) const; /* No definition.  */
  59   template <class T> bool operator!= (T) const; /* No definition.  */
  60 };
  61
  62 static int
  63 do_test ()
  64 {
  65   {
  66     no_int value;
  67     assert (value);
  68   }
  69
  70   {
  71     bool_and_int value;
  72     assert (value);
  73   }
  74
  75   return 0;
  76 }
  77
  78 #include <support/test-driver.c>