ceph/src/jaegertracing/opentelemetry-cpp/api/include/opentelemetry/nostd/detail/variant_size.h

   1 #pragma once
   2
   3 #include <type_traits>
   4
   5 #include "opentelemetry/nostd/detail/variant_fwd.h"
   6 #include "opentelemetry/version.h"
   7
   8 OPENTELEMETRY_BEGIN_NAMESPACE
   9 namespace nostd
  10 {
  11 template <typename T>
  12 struct variant_size;
  13
  14 template <typename T>
  15 struct variant_size<const T> : variant_size<T>
  16 {};
  17
  18 template <typename T>
  19 struct variant_size<volatile T> : variant_size<T>
  20 {};
  21
  22 template <typename T>
  23 struct variant_size<const volatile T> : variant_size<T>
  24 {};
  25
  26 template <typename... Ts>
  27 struct variant_size<variant<Ts...>> : std::integral_constant<size_t, sizeof...(Ts)>
  28 {};
  29 }  // namespace nostd
  30 OPENTELEMETRY_END_NAMESPACE