gistfile1.cs

//IDataErrorInfo as a Mixed in implementation.

[MixIn(typeof(DataErrorInfoImpl)]
public class Person 
{
  [Required]
  public string FirstName{get;set;}
  public string LastName {get;set;}
}



public class DataErrorInfoImpl : IDataErrorInfo
{
  public string this[string columnName]()
  { 
    // data annotations code to retrieve errors
  }

  public string Errors(){ //other code }
}


//produces:

public class Person 
{
  [Required]
  public string FirstName{get;set;}
  public string LastName {get;set;}

  string IDataErrorInfo.this[string columnName]()
  { 
    // data annotations code to retrieve errors
  }

  string IDataErrorInfo.Errors(){ //other code }
}

//Remove mixing attribute and reference from the assembly.