Extension Types for easier (and strongly typed) Attribute checks

Implementation.cs

public static class AttributeExtensions
{
  // Attribute.IsDefined shortcuts
  public static bool HasAttribute<T>(this object element) where T : Attribute
  { return Attribute.IsDefined(element.GetType(), typeof(T)); }
  public static bool HasAttribute<T>(this object element, bool inherit) where T : Attribute
  { return Attribute.IsDefined(element.GetType(), typeof(T), inherit); }
  public static bool HasAttribute<T>(this Assembly element) where T : Attribute
  { return Attribute.IsDefined(element, typeof(T)); }
  public static bool HasAttribute<T>(this Assembly element, bool inherit) where T : Attribute
  { return Attribute.IsDefined(element, typeof(T), inherit); }
  public static bool HasAttribute<T>(this MemberInfo element) where T : Attribute
  { return Attribute.IsDefined(element, typeof(T)); }
  public static bool HasAttribute<T>(this MemberInfo element, bool inherit) where T : Attribute
  { return Attribute.IsDefined(element, typeof(T), inherit); }
  public static bool HasAttribute<T>(this Module element) where T : Attribute
  { return Attribute.IsDefined(element, typeof(T)); }
  public static bool HasAttribute<T>(this Module element, bool inherit) where T : Attribute
  { return Attribute.IsDefined(element, typeof(T), inherit); }
  public static bool HasAttribute<T>(this ParameterInfo element) where T : Attribute
  { return Attribute.IsDefined(element, typeof(T)); }
  public static bool HasAttribute<T>(this ParameterInfo element, bool inherit) where T : Attribute
  { return Attribute.IsDefined(element, typeof(T), inherit); }

  // Attribute.GetCustomAttribute shotcuts
  public static T GetAttribute<T>(this object element) where T : Attribute
  { return Attribute.GetCustomAttribute(element.GetType(), typeof(T)) as T; }
  public static T GetAttribute<T>(this object element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttribute(element.GetType(), typeof(T), inherit) as T; }
  public static T GetAttribute<T>(this Assembly element) where T : Attribute
  { return Attribute.GetCustomAttribute(element, typeof(T)) as T; }
  public static T GetAttribute<T>(this Assembly element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttribute(element, typeof(T), inherit) as T; }
  public static T GetAttribute<T>(this MemberInfo element) where T : Attribute
  { return Attribute.GetCustomAttribute(element, typeof(T)) as T; }
  public static T GetAttribute<T>(this MemberInfo element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttribute(element, typeof(T), inherit) as T; }
  public static T GetAttribute<T>(this Module element) where T : Attribute
  { return Attribute.GetCustomAttribute(element, typeof(T)) as T; }
  public static T GetAttribute<T>(this Module element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttribute(element, typeof(T), inherit) as T; }
  public static T GetAttribute<T>(this ParameterInfo element) where T : Attribute
  { return Attribute.GetCustomAttribute(element, typeof(T)) as T; }
  public static T GetAttribute<T>(this ParameterInfo element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttribute(element, typeof(T), inherit) as T; }

  // Attribute.GetCustomAttributes shortcuts
  public static T[] GetAttributes<T>(this object element) where T : Attribute
  { return Attribute.GetCustomAttributes(element.GetType(), typeof(T)) as T[]; }
  public static T[] GetAttributes<T>(this object element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttributes(element.GetType(), typeof(T), inherit) as T[]; }
  public static T[] GetAttributes<T>(this Assembly element) where T : Attribute
  { return Attribute.GetCustomAttributes(element, typeof(T)) as T[]; }
  public static T[] GetAttributes<T>(this Assembly element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttributes(element, typeof(T), inherit) as T[]; }
  public static T[] GetAttributes<T>(this MemberInfo element) where T : Attribute
  { return Attribute.GetCustomAttributes(element, typeof(T)) as T[]; }
  public static T[] GetAttributes<T>(this MemberInfo element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttributes(element, typeof(T), inherit) as T[]; }
  public static T[] GetAttributes<T>(this Module element) where T : Attribute
  { return Attribute.GetCustomAttributes(element, typeof(T)) as T[]; }
  public static T[] GetAttributes<T>(this Module element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttributes(element, typeof(T), inherit) as T[]; }
  public static T[] GetAttributes<T>(this ParameterInfo element) where T : Attribute
  { return Attribute.GetCustomAttributes(element, typeof(T)) as T[]; }
  public static T[] GetAttributes<T>(this ParameterInfo element, bool inherit) where T : Attribute
  { return Attribute.GetCustomAttributes(element, typeof(T), inherit) as T[]; }

  // ICustomAttributeProvider shortcuts (contributed by AutoRevit, thanks!)
  public static bool IsAttributeDefined<t>(this ICustomAttributeProvider provider, bool inherit = true) where T : Attribute
  { return provider.IsDefined(typeof(T), inherit); }
  public static T[] GetAttributes</t><t>(this ICustomAttributeProvider provider, bool inherit = true) where T : Attribute
  { return provider.GetCustomAttributes(typeof(T), inherit) as T[]; }
  public static T GetFirstAttribute</t><t>(this ICustomAttributeProvider provider, inherit = true) where T : Attribute
  { return provider.GetAttributes</t><t>(inherit).FirstOrDefault(); }
}

Usage.cs

var instance = new SomeClass();

// How to check for attributes using the extension methods.
bool hasMarkerAttribute = instance.HasAttribute<MyMarkerAttribute>();

// How to check for marker interface using unfair compiler sugar. ;)
bool hasMarkerInterface = instance is IMyMarkerInterface;

// Not that much shorter, right?