private static ITypeSymbol GetRegularExpressionType(SemanticModel semanticModel, SyntaxNode node)
{
// regular case. always use ConvertedType to get implicit conversion right.
var expression = node.GetUnparenthesizedExpression();
var info = semanticModel.GetTypeInfo(expression);
var conv = semanticModel.GetConversion(expression);
if (info.ConvertedType == null || info.ConvertedType.IsErrorType())
{
// there is no implicit conversion involved. no need to go further
return info.Type;
}
// always use converted type if method group
if ((!node.IsKind(SyntaxKind.ObjectCreationExpression) && semanticModel.GetMemberGroup(expression).Length > 0) ||
IsCoClassImplicitConversion(info, conv, semanticModel.Compilation.CoClassType()))
{
return info.ConvertedType;
}
// check implicit conversion
if (conv.IsImplicit && (conv.IsConstantExpression || conv.IsEnumeration))
{
return info.ConvertedType;
}
// always try to use type that is more specific than object type if possible.
return !info.Type.IsObjectType() ? info.Type : info.ConvertedType;
}
