/*
 * Copyright 2007-2012 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// Not yet used in PDFsharp.

#pragma warning disable 1591

// Currently not used.
#if true_
using System;
using System.ComponentModel;

namespace JetBrains.Annotations
{
    /// <summary>
    /// Indicates that marked element should be localized or not.
    /// </summary>
    /// <example>
    /// <code>
    /// [LocalizationRequiredAttribute(true)]
    /// public class Foo
    /// {
    ///   private string str = "my string"; // Warning: Localizable string
    /// }
    /// </code>
    /// </example>
    [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = true)]
    public sealed class LocalizationRequiredAttribute : Attribute
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="LocalizationRequiredAttribute"/> class with
        /// <see cref="Required"/> set to <see langword="true"/>.
        /// </summary>
        public LocalizationRequiredAttribute()
            : this(true)
        { }

        /// <summary>
        /// Initializes a new instance of the <see cref="LocalizationRequiredAttribute"/> class.
        /// </summary>
        /// <param name="required"><c>true</c> if a element should be localized; otherwise, <c>false</c>.</param>
        public LocalizationRequiredAttribute(bool required)
        {
            Required = required;
        }

        /// <summary>
        /// Gets a value indicating whether a element should be localized.
        /// <value><c>true</c> if a element should be localized; otherwise, <c>false</c>.</value>
        /// </summary>
        [UsedImplicitly]
        public bool Required { get; private set; }

        /// <summary>
        /// Returns whether the value of the given object is equal to the current <see cref="LocalizationRequiredAttribute"/>.
        /// </summary>
        /// <param name="obj">The object to test the value equality of. </param>
        /// <returns>
        /// <c>true</c> if the value of the given object is equal to that of the current; otherwise, <c>false</c>.
        /// </returns>
        public override bool Equals(object obj)
        {
            var attribute = obj as LocalizationRequiredAttribute;
            return attribute != null && attribute.Required == Required;
        }

        /// <summary>
        /// Returns the hash code for this instance.
        /// </summary>
        /// <returns>A hash code for the current <see cref="LocalizationRequiredAttribute"/>.</returns>
        public override int GetHashCode()
        {
            return base.GetHashCode();
        }
    }

    /// <summary>
    /// Indicates that the marked method builds string by format pattern and (optional) arguments. 
    /// Parameter, which contains format string, should be given in constructor.
    /// The format string should be in <see cref="string.Format(IFormatProvider,string,object[])"/> -like form
    /// </summary>
    /// <example>
    /// <code>
    /// [StringFormatMethod("message")]
    /// public void ShowError(string message, params object[] args)
    /// {
    ///   //Do something
    /// }
    /// public void Foo()
    /// {
    ///   ShowError("Failed: {0}"); // Warning: Non-existing argument in format string
    /// }
    /// </code>
    /// </example>
    [AttributeUsage(AttributeTargets.Constructor | AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
    public sealed class StringFormatMethodAttribute : Attribute
    {
        /// <summary>
        /// Initializes new instance of StringFormatMethodAttribute
        /// </summary>
        /// <param name="formatParameterName">Specifies which parameter of an annotated method should be treated as format-string</param>
        public StringFormatMethodAttribute(string formatParameterName)
        {
            FormatParameterName = formatParameterName;
        }

        /// <summary>
        /// Gets format parameter name
        /// </summary>
        [UsedImplicitly]
        public string FormatParameterName { get; private set; }
    }

    /// <summary>
    /// Indicates that the function argument should be string literal and match one of the parameters
    /// of the caller function.
    /// For example, ReSharper annotates the parameter of <see cref="System.ArgumentNullException"/>.
    /// </summary>
    /// <example>
    /// <code>
    /// public void Foo(string param)
    /// {
    ///   if (param == null)
    ///     throw new ArgumentNullException("par"); // Warning: Cannot resolve symbol
    /// }
    /// </code>
    /// </example>
    [AttributeUsage(AttributeTargets.Parameter, AllowMultiple = false, Inherited = true)]
    public sealed class InvokerParameterNameAttribute : Attribute { }

    /// <summary>
    /// Indicates that the method is contained in a type that implements
    /// <see cref="System.ComponentModel.INotifyPropertyChanged"/> interface
    /// and this method is used to notify that some property value changed.
    /// </summary>
    /// <remarks>
    /// The method should be non-static and conform to one of the supported signatures:
    /// <list>
    /// <item><c>NotifyChanged(string)</c></item>
    /// <item><c>NotifyChanged(params string[])</c></item>
    /// <item><c>NotifyChanged{T}(Expression{Func{T}})</c></item>
    /// <item><c>NotifyChanged{T,U}(Expression{Func{T,U}})</c></item>
    /// <item><c>SetProperty{T}(ref T, T, string)</c></item>
    /// </list>
    /// </remarks>
    /// <example>
    /// <code>
    /// public class Foo : INotifyPropertyChanged
    /// {
    ///   public event PropertyChangedEventHandler PropertyChanged;
    ///
    ///   [NotifyPropertyChangedInvocator]
    ///   protected virtual void NotifyChanged(string propertyName)
    ///   {}
    ///
    ///   private string _name;
    ///   public string Name
    ///   {
    ///     get { return _name; }
    ///     set
    ///     {
    ///       _name = value;
    ///       NotifyChanged("LastName"); // Warning
    ///     }
    ///   }
    /// }
    /// </code>
    /// Examples of generated notifications:
    /// <list>
    /// <item><c>NotifyChanged("Property")</c></item>
    /// <item><c>NotifyChanged(() => Property)</c></item>
    /// <item><c>NotifyChanged((VM x) => x.Property)</c></item>
    /// <item><c>SetProperty(ref myField, value, "Property")</c></item>
    /// </list>
    /// </example>
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
    public sealed class NotifyPropertyChangedInvocatorAttribute : Attribute
    {
        public NotifyPropertyChangedInvocatorAttribute() { }
        public NotifyPropertyChangedInvocatorAttribute(string parameterName)
        {
            ParameterName = parameterName;
        }

        [UsedImplicitly]
        public string ParameterName { get; private set; }
    }

    /// <summary>
    /// Indicates that the value of the marked element could be <c>null</c> sometimes, 
    /// so the check for <c>null</c> is necessary before its usage.
    /// </summary>
    /// <example>
    /// <code>
    /// [CanBeNull]
    /// public object Test()
    /// {
    ///   return null;
    /// }
    /// 
    /// public void UseTest()
    /// {
    ///   var p = Test(); 
    ///   var s = p.ToString(); // Warning: Possible 'System.NullReferenceException' 
    /// }
    /// </code>
    /// </example>
    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.Delegate | AttributeTargets.Field, AllowMultiple = false, Inherited = true)]
    public sealed class CanBeNullAttribute : Attribute { }

    /// <summary>
    /// Indicates that the value of the marked element could never be <c>null</c>
    /// </summary>
    /// <example>
    /// <code>
    /// [NotNull]
    /// public object Foo()
    /// {
    ///   return null; // Warning: Possible 'null' assignment
    /// } 
    /// </code>
    /// </example>
    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.Delegate | AttributeTargets.Field, AllowMultiple = false, Inherited = true)]
    public sealed class NotNullAttribute : Attribute { }

    /// <summary>
    /// Describes dependency between method input and output.
    /// </summary>
    /// <syntax>
    /// <p>Function Definition Table syntax:</p>
    /// <list>
    /// <item>FDT      ::= FDTRow [;FDTRow]*</item>
    /// <item>FDTRow   ::= Input =&gt; Output | Output &lt;= Input</item>
    /// <item>Input    ::= ParameterName: Value [, Input]*</item>
    /// <item>Output   ::= [ParameterName: Value]* {halt|stop|void|nothing|Value}</item>
    /// <item>Value    ::= true | false | null | notnull | canbenull</item>
    /// </list>
    /// If method has single input parameter, its name could be omitted. <br/>
    /// Using <c>halt</c> (or <c>void</c>/<c>nothing</c>, which is the same) for method output means that the methos doesn't return normally. <br/>
    /// <c>canbenull</c> annotation is only applicable for output parameters. <br/>
    /// You can use multiple <c>[ContractAnnotation]</c> for each FDT row, or use single attribute with rows separated by semicolon. <br/>
    /// </syntax>
    /// <examples>
    /// <list>
    /// <item><code>
    /// [ContractAnnotation("=> halt")]
    /// public void TerminationMethod()
    /// </code></item>
    /// <item><code>
    /// [ContractAnnotation("halt &lt;= condition: false")]
    /// public void Assert(bool condition, string text) // Regular Assertion method
    /// </code></item>
    /// <item><code>
    /// [ContractAnnotation("s:null => true")]
    /// public bool IsNullOrEmpty(string s) // String.IsNullOrEmpty
    /// </code></item>
    /// <item><code>
    /// // A method that returns null if the parameter is null, and not null if the parameter is not null
    /// [ContractAnnotation("null => null; notnull => notnull")]
    /// public object Transform(object data) 
    /// </code></item>
    /// <item><code>
    /// [ContractAnnotation("s:null=>false; =>true,result:notnull; =>false, result:null")]
    /// public bool TryParse(string s, out Person result)
    /// </code></item>
    /// </list>
    /// </examples>
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
    public sealed class ContractAnnotationAttribute : Attribute
    {
        public ContractAnnotationAttribute([NotNull] string fdt)
            : this(fdt, false)
        {
        }

        public ContractAnnotationAttribute([NotNull] string fdt, bool forceFullStates)
        {
            FDT = fdt;
            ForceFullStates = forceFullStates;
        }

        public string FDT { get; private set; }
        public bool ForceFullStates { get; private set; }
    }

    /// <summary>
    /// Indicates that the value of the marked type (or its derivatives)
    /// cannot be compared using '==' or '!=' operators and <c>Equals()</c> should be used instead.
    /// However, using '==' or '!=' for comparison with <c>null</c> is always permitted.
    /// </summary>
    /// <example>
    /// <code>
    /// [CannotApplyEqualityOperator]
    /// class NoEquality
    /// {
    /// }
    /// 
    /// class UsesNoEquality
    /// {
    ///   public void Test()
    ///   {
    ///     var ca1 = new NoEquality();
    ///     var ca2 = new NoEquality();
    /// 
    ///     if (ca1 != null) // OK
    ///     {
    ///       bool condition = ca1 == ca2; // Warning
    ///     }
    ///   }
    /// }
    /// </code>
    /// </example>
    [AttributeUsage(AttributeTargets.Interface | AttributeTargets.Class | AttributeTargets.Struct, AllowMultiple = false, Inherited = true)]
    public sealed class CannotApplyEqualityOperatorAttribute : Attribute { }

    /// <summary>
    /// When applied to a target attribute, specifies a requirement for any type marked with 
    /// the target attribute to implement or inherit specific type or types.
    /// </summary>
    /// <example>
    /// <code>
    /// [BaseTypeRequired(typeof(IComponent)] // Specify requirement
    /// public class ComponentAttribute : Attribute 
    /// {}
    /// 
    /// [Component] // ComponentAttribute requires implementing IComponent interface
    /// public class MyComponent : IComponent
    /// {}
    /// </code>
    /// </example>
    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
    [BaseTypeRequired(typeof(Attribute))]
    public sealed class BaseTypeRequiredAttribute : Attribute
    {
        /// <summary>
        /// Initializes new instance of BaseTypeRequiredAttribute
        /// </summary>
        /// <param name="baseType">Specifies which types are required</param>
        public BaseTypeRequiredAttribute(Type baseType)
        {
            BaseTypes = new[] { baseType };
        }

        /// <summary>
        /// Gets enumerations of specified base types
        /// </summary>
        public Type[] BaseTypes { get; private set; }
    }

    /// <summary>
    /// Indicates that the marked symbol is used implicitly (e.g. via reflection, in external library),
    /// so this symbol will not be marked as unused (as well as by other usage inspections)
    /// </summary>
    [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = true)]
    public sealed class UsedImplicitlyAttribute : Attribute
    {
        [UsedImplicitly]
        public UsedImplicitlyAttribute()
            : this(ImplicitUseKindFlags.Default, ImplicitUseTargetFlags.Default)
        { }

        [UsedImplicitly]
        public UsedImplicitlyAttribute(ImplicitUseKindFlags useKindFlags, ImplicitUseTargetFlags targetFlags)
        {
            UseKindFlags = useKindFlags;
            TargetFlags = targetFlags;
        }

        [UsedImplicitly]
        public UsedImplicitlyAttribute(ImplicitUseKindFlags useKindFlags)
            : this(useKindFlags, ImplicitUseTargetFlags.Default)
        { }

        [UsedImplicitly]
        public UsedImplicitlyAttribute(ImplicitUseTargetFlags targetFlags)
            : this(ImplicitUseKindFlags.Default, targetFlags)
        { }

        [UsedImplicitly]
        public ImplicitUseKindFlags UseKindFlags { get; private set; }

        /// <summary>
        /// Gets value indicating what is meant to be used
        /// </summary>
        [UsedImplicitly]
        public ImplicitUseTargetFlags TargetFlags { get; private set; }
    }

    /// <summary>
    /// Should be used on attributes and causes ReSharper
    /// to not mark symbols marked with such attributes as unused (as well as by other usage inspections)
    /// </summary>
    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = true)]
    public sealed class MeansImplicitUseAttribute : Attribute
    {
        [UsedImplicitly]
        public MeansImplicitUseAttribute()
            : this(ImplicitUseKindFlags.Default, ImplicitUseTargetFlags.Default)
        { }

        [UsedImplicitly]
        public MeansImplicitUseAttribute(ImplicitUseKindFlags useKindFlags, ImplicitUseTargetFlags targetFlags)
        {
            UseKindFlags = useKindFlags;
            TargetFlags = targetFlags;
        }

        [UsedImplicitly]
        public MeansImplicitUseAttribute(ImplicitUseKindFlags useKindFlags)
            : this(useKindFlags, ImplicitUseTargetFlags.Default)
        {
        }

        [UsedImplicitly]
        public MeansImplicitUseAttribute(ImplicitUseTargetFlags targetFlags)
            : this(ImplicitUseKindFlags.Default, targetFlags)
        { }

        [UsedImplicitly]
        public ImplicitUseKindFlags UseKindFlags { get; private set; }

        /// <summary>
        /// Gets value indicating what is meant to be used
        /// </summary>
        [UsedImplicitly]
        public ImplicitUseTargetFlags TargetFlags { get; private set; }
    }

    [Flags]
    public enum ImplicitUseKindFlags
    {
        Default = Access | Assign | InstantiatedWithFixedConstructorSignature,

        /// <summary>
        /// Only entity marked with attribute considered used
        /// </summary>
        Access = 1,

        /// <summary>
        /// Indicates implicit assignment to a member
        /// </summary>
        Assign = 2,

        /// <summary>
        /// Indicates implicit instantiation of a type with fixed constructor signature.
        /// That means any unused constructor parameters won't be reported as such.
        /// </summary>
        InstantiatedWithFixedConstructorSignature = 4,

        /// <summary>
        /// Indicates implicit instantiation of a type
        /// </summary>
        InstantiatedNoFixedConstructorSignature = 8,
    }

    /// <summary>
    /// Specify what is considered used implicitly when marked with <see cref="MeansImplicitUseAttribute"/> or <see cref="UsedImplicitlyAttribute"/>
    /// </summary>
    [Flags]
    public enum ImplicitUseTargetFlags
    {
        Default = Itself,

        Itself = 1,

        /// <summary>
        /// Members of entity marked with attribute are considered used
        /// </summary>
        Members = 2,

        /// <summary>
        /// Entity marked with attribute and all its members considered used
        /// </summary>
        WithMembers = Itself | Members
    }

    /// <summary>
    /// This attribute is intended to mark publicly available API which should not be removed and so is treated as used.
    /// </summary>
    [MeansImplicitUse]
    public sealed class PublicAPIAttribute : Attribute
    {
        public PublicAPIAttribute() { }
        public PublicAPIAttribute(string comment) { }
    }

    /// <summary>
    /// Tells code analysis engine if the parameter is completely handled when the invoked method is on stack. 
    /// If the parameter is a delegate, indicates that delegate is executed while the method is executed.
    /// If the parameter is an enumerable, indicates that it is enumerated while the method is executed.
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter, Inherited = true)]
    public sealed class InstantHandleAttribute : Attribute { }


    /// <summary>
    /// Indicates that a method does not make any observable state changes.
    /// The same as <see cref="System.Diagnostics.Contracts.PureAttribute"/>
    /// </summary>
    /// <example>
    /// <code>
    /// [Pure]
    /// private int Multiply(int x, int y)
    /// {
    ///   return x*y;
    /// }
    ///
    /// public void Foo()
    /// {
    ///   const int a=2, b=2;
    ///   Multiply(a, b); // Waring: Return value of pure method is not used
    /// }
    /// </code>
    /// </example>
    [AttributeUsage(AttributeTargets.Method, Inherited = true)]
    public sealed class PureAttribute : Attribute { }

    /// <summary>
    /// Indicates that a parameter is a path to a file or a folder within a web project.
    /// Path can be relative or absolute, starting from web root (~).
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter)]
    public class PathReferenceAttribute : Attribute
    {
        public PathReferenceAttribute() { }

        [UsedImplicitly]
        public PathReferenceAttribute([PathReference] string basePath)
        {
            BasePath = basePath;
        }

        [UsedImplicitly]
        public string BasePath { get; private set; }
    }

    // ASP.NET MVC attributes

    /// <summary>
    /// ASP.NET MVC attribute. If applied to a parameter, indicates that the parameter is an MVC action.
    /// If applied to a method, the MVC action name is calculated implicitly from the context.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.Mvc.Html.ChildActionExtensions.RenderAction(HtmlHelper, String)"/>
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Method)]
    public sealed class AspMvcActionAttribute : Attribute
    {
        [UsedImplicitly]
        public string AnonymousProperty { get; private set; }

        public AspMvcActionAttribute() { }

        public AspMvcActionAttribute(string anonymousProperty)
        {
            AnonymousProperty = anonymousProperty;
        }
    }

    /// <summary>
    /// ASP.NET MVC attribute. Indicates that a parameter is an MVC araa.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.Mvc.Html.ChildActionExtensions.RenderAction(HtmlHelper, String)"/>
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter)]
    public sealed class AspMvcAreaAttribute : PathReferenceAttribute
    {
        [UsedImplicitly]
        public string AnonymousProperty { get; private set; }

        [UsedImplicitly]
        public AspMvcAreaAttribute() { }

        public AspMvcAreaAttribute(string anonymousProperty)
        {
            AnonymousProperty = anonymousProperty;
        }
    }

    /// <summary>
    /// ASP.NET MVC attribute. If applied to a parameter, indicates that the parameter is an MVC controller.
    /// If applied to a method, the MVC controller name is calculated implicitly from the context.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.Mvc.Html.ChildActionExtensions.RenderAction(HtmlHelper, String, String)"/> 
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Method)]
    public sealed class AspMvcControllerAttribute : Attribute
    {
        [UsedImplicitly]
        public string AnonymousProperty { get; private set; }

        public AspMvcControllerAttribute() { }

        public AspMvcControllerAttribute(string anonymousProperty)
        {
            AnonymousProperty = anonymousProperty;
        }
    }

    /// <summary>
    /// ASP.NET MVC attribute. Indicates that a parameter is an MVC Master.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.Mvc.Controller.View(String, String)"/>
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter)]
    public sealed class AspMvcMasterAttribute : Attribute { }

    /// <summary>
    /// ASP.NET MVC attribute. Indicates that a parameter is an MVC model type.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.Mvc.Controller.View(String, Object)"/>
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter)]
    public sealed class AspMvcModelTypeAttribute : Attribute { }

    /// <summary>
    /// ASP.NET MVC attribute. If applied to a parameter, indicates that the parameter is an MVC partial view.
    /// If applied to a method, the MVC partial view name is calculated implicitly from the context.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.Mvc.Html.RenderPartialExtensions.RenderPartial(HtmlHelper, String)"/>
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Method)]
    public sealed class AspMvcPartialViewAttribute : PathReferenceAttribute { }

    /// <summary>
    /// ASP.NET MVC attribute. Allows disabling all inspections for MVC views within a class or a method.
    /// </summary>
    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]
    public sealed class AspMvcSupressViewErrorAttribute : Attribute { }

    /// <summary>
    /// ASP.NET MVC attribute. Indicates that a parameter is an MVC display template.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.Mvc.Html.DisplayExtensions.DisplayForModel(HtmlHelper, String)"/>
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter)]
    public sealed class AspMvcDisplayTemplateAttribute : Attribute { }

    /// <summary>
    /// ASP.NET MVC attribute. Indicates that a parameter is an MVC editor template.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.Mvc.Html.EditorExtensions.EditorForModel(HtmlHelper, String)"/>
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter)]
    public sealed class AspMvcEditorTemplateAttribute : Attribute { }

    /// <summary>
    /// ASP.NET MVC attribute. If applied to a parameter, indicates that the parameter is an MVC view.
    /// If applied to a method, the MVC view name is calculated implicitly from the context.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.Mvc.Controller.View(Object)"/>
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Method)]
    public sealed class AspMvcViewAttribute : PathReferenceAttribute { }

    /// <summary>
    /// ASP.NET MVC attribute. When applied to a parameter of an attribute,
    /// indicates that this parameter is an MVC action name.
    /// </summary>
    /// <example>
    /// <code>
    /// [ActionName("Foo")]
    /// public ActionResult Login(string returnUrl)
    /// {
    ///   ViewBag.ReturnUrl = Url.Action("Foo"); // OK
    ///   return RedirectToAction("Bar"); // Error: Cannot resolve action
    /// }
    /// </code>
    /// </example>
    [AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Property)]
    public sealed class AspMvcActionSelectorAttribute : Attribute { }

    // Razor attributes

    /// <summary>
    /// Razor attribute. Indicates that a parameter or a method is a Razor section.
    /// Use this attribute for custom wrappers similar to 
    /// <see cref="System.Web.WebPages.WebPageBase.RenderSection(String)"/>
    /// </summary>
    [AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Method, Inherited = true)]
    public sealed class RazorSectionAttribute : Attribute { }
}
#endif