source: trunk/sources/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Resolver/CastResolveResult.cs @ 13401

// Copyright (c) 2010-2013 AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

using System;
using ICSharpCode.NRefactory.Semantics;
using ICSharpCode.NRefactory.TypeSystem;

namespace ICSharpCode.NRefactory.CSharp.Resolver
{
  /// <summary>
  /// Represents an explicitly applied conversion (CastExpression or AsExpression)
  /// (a result belonging to an AST node; not implicitly inserted 'between' nodes).
  /// </summary>
  class CastResolveResult : ConversionResolveResult
  {
    // The reason this class exists is that for code like this:
    //    int i = ...;
    //    long n = 0;
    //    n = n + (long)i;
    // The resolver will produce (and process) an CastResolveResult for the cast,
    // (with Conversion = implicit numeric conversion)
    // and then pass it into CSharpResolver.ResolveBinaryOperator().
    // That method normally wraps input arguments into another conversion
    // (the implicit conversion applied by the operator).
    // However, identity conversions do not cause the creation of ConversionResolveResult instances,
    // so the OperatorResolveResult's argument will be the CastResolveResult
    // of the cast.
    // Without this class (and instead using ConversionResolveResult for both purposes),
    // it would be hard for the conversion-processing code
    // in the ResolveVisitor to distinguish the existing conversion from the CastExpression
    // from an implicit conversion introduced by the binary operator.
    // This would cause the conversion to be processed yet again.
    // The following unit tests would fail without this class:
    //  * CastTests.ExplicitConversion_In_Assignment
    //  * FindReferencesTest.FindReferencesForOpImplicitInAssignment_ExplicitCast
    //  * CS0029InvalidConversionIssueTests.ExplicitConversionFromUnknownType
    
    public CastResolveResult(ConversionResolveResult rr)
      : base(rr.Type, rr.Input, rr.Conversion, rr.CheckForOverflow)
    {
    }
    
    public CastResolveResult(IType targetType, ResolveResult input, Conversion conversion, bool checkForOverflow)
      : base(targetType, input, conversion, checkForOverflow)
    {
    }
  }
}