libstdc++-v3/testsuite/std/format/arguments/112607.cc

   1 // { dg-do compile { target c++20 } }
   2
   3 // PR libstdc++/112607
   4 // _Normalize does not consider char_type for the basic_string_view case
   5
   6 #include <format>
   7
   8 template<typename T>
   9 struct Alloc
  10 {
  11   using value_type = T;
  12   Alloc() = default;
  13   template<typename U>
  14     Alloc(const Alloc<U>&) { }
  15   T* allocate(std::size_t);
  16   void deallocate(T*, std::size_t);
  17   bool operator==(const Alloc&) const;
  18 };
  19
  20 template<typename C>
  21 using String = std::basic_string<C, std::char_traits<C>, Alloc<C>>;
  22
  23 template<>
  24 struct std::formatter<String<wchar_t>> : std::formatter<std::string> {
  25   auto format(const String<wchar_t>&, auto& ctx) const {
  26     return std::formatter<std::string>::format(" ", ctx);
  27   }
  28 };
  29
  30 std::string str = std::format("{}", String<wchar_t>{});