internal static NonGenericEnumInfo GetNonGenericEnumInfo(Type enumType)
{
Preconditions.NotNull(enumType, nameof(enumType));
var nonGenericEnumInfos = _nonGenericEnumInfos;
NonGenericEnumInfo info;
if (!nonGenericEnumInfos.TryGetValue(enumType, out info))
{
if (enumType.IsEnum())
{
var closedEnumsType = typeof(Enums<>).MakeGenericType(enumType);
info = new NonGenericEnumInfo((IEnumInfo)closedEnumsType.
#if TYPE_REFLECTION
GetField("Info", BindingFlags.Static | BindingFlags.Public)
#else
GetTypeInfo().GetDeclaredField("Info")
#endif
.GetValue(null), false);
}
else
{
var nonNullableEnumType = Nullable.GetUnderlyingType(enumType);
if (nonNullableEnumType?.IsEnum() != true)
{
throw new ArgumentException("must be an enum type", nameof(enumType));
}
info = new NonGenericEnumInfo(GetInfo(nonNullableEnumType), true);
}
Dictionary<Type, NonGenericEnumInfo> oldNonGenericEnumInfos;
do
{
NonGenericEnumInfo foundInfo;
if (nonGenericEnumInfos.TryGetValue(enumType, out foundInfo))
{
return foundInfo;
}
oldNonGenericEnumInfos = nonGenericEnumInfos;
nonGenericEnumInfos = new Dictionary<Type, NonGenericEnumInfo>(nonGenericEnumInfos);
nonGenericEnumInfos.Add(enumType, info);
} while ((nonGenericEnumInfos = Interlocked.CompareExchange(ref _nonGenericEnumInfos, nonGenericEnumInfos, oldNonGenericEnumInfos)) != oldNonGenericEnumInfos);
}
return info;
}
internal static bool EqualsInternal(NonGenericEnumInfo info, object value, object other)
{
var enumInfo = info.EnumInfo;
if (info.IsNullable)
{
if (value == null)
{
if (other == null)
{
return true;
}
enumInfo.ToObject(other);
return false;
}
if (other == null)
{
enumInfo.ToObject(value);
return false;
}
}
return enumInfo.Equals(value, other);
}
internal static int CompareToInternal(NonGenericEnumInfo info, object value, object other)
{
var enumInfo = info.EnumInfo;
if (info.IsNullable)
{
if (value == null)
{
if (other == null)
{
return 0;
}
enumInfo.ToObject(other);
return -1;
}
if (other == null)
{
enumInfo.ToObject(value);
return 1;
}
}
return enumInfo.CompareTo(value, other);
}
/// <summary>
/// The <see cref="NonGenericEnumComparer"/> constructor.
/// </summary>
/// <param name="enumType">The enum type.</param>
/// <exception cref="ArgumentNullException"><paramref name="enumType"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentException"><paramref name="enumType"/> is not an enum type.</exception>
public NonGenericEnumComparer(Type enumType)
{
_info = NonGenericEnums.GetNonGenericEnumInfo(enumType);
}
