source: branches/RemoveBackwardsCompatibility/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Resolver/CastResolveResult.cs @ 14815

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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)
    {
    }
  }
}