libcxx/test/std/localization/locales/locale.global.templates/use_facet.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // <locale>
  10
  11 // template <class Facet> const Facet& use_facet(const locale& loc);
  12
  13 #include <locale>
  14 #include <cassert>
  15 #include <typeinfo>
  16
  17 #include "test_macros.h"
  18
  19 int facet_count = 0;
  20
  21 struct my_facet
  22     : public std::locale::facet
  23 {
  24     static std::locale::id id;
  25
  26     bool im_alive;
  27
  28     my_facet() : im_alive(true) {++facet_count;}
  29     ~my_facet() {im_alive = false; --facet_count;}
  30 };
  31
  32 std::locale::id my_facet::id;
  33
  34 int main(int, char**)
  35 {
  36 #ifndef TEST_HAS_NO_EXCEPTIONS
  37     try
  38     {
  39         const my_facet& f = std::use_facet<my_facet>(std::locale());
  40         ((void)f); // Prevent unused warning
  41         assert(false);
  42     }
  43     catch (std::bad_cast&)
  44     {
  45     }
  46 #endif
  47     const my_facet* fp = 0;
  48     {
  49         std::locale loc(std::locale(), new my_facet);
  50         const my_facet& f = std::use_facet<my_facet>(loc);
  51         assert(f.im_alive);
  52         fp = &f;
  53         assert(fp->im_alive);
  54         assert(facet_count == 1);
  55     }
  56     assert(facet_count == 0);
  57
  58   return 0;
  59 }