MVVM Light additional ObservableObject.Set() methods to allow arbitrary backing fields & easier object wrapping.

mvvmlightset.cs

// This would allow using properties as the backing fields.
// Useful when making models which wrap an object and use an
// instance of that object for the backing field, as
// shown in the example below.

// Usage:
public class PersonViewModel : EasyObservableObject
{
    private Person p = new Person();
    public string FirstName
    {
        get { return p.FirstName; }
        set { Set("FirstName", x => p.FirstName = x, p.FirstName, value); }
    }
    public string LastName
    {
        get { return p.LastName; }
        set { Set(x => p.LastName = x, p.LastName, value); }
    }
}

// Implementationn:

/// <summary>
/// Assigns a new value to the property. Then, raises the
/// PropertyChanged event if needed.
/// </summary>
/// <typeparam name="T">The type of property that
/// changed.</typeparam>
/// <param name="setField">Action to execute to set the
/// field's value.</param>
/// <param name="oldValue">The current value of the field.</param>
/// <param name="newValue">The property's value after the change
/// occured.</param>
/// <param name="propertyName">The name of the property that changed.</param>
/// <returns>True if the PropertyChanged event has been raised,
/// false otherwise. The event is not raised if the old
/// value is equal to the new value.</returns>
protected bool Set<T>(
    Action<T> setField,
    T oldValue,
    T newValue,
    [CallerMemberName]string propertyName = null)
{
    return Set(propertyName, setField, oldValue, newValue);
}

/// <summary>
/// Assigns a new value to the property. Then, raises the
/// PropertyChanged event if needed.
/// </summary>
/// <typeparam name="T">The type of property that
/// changed.</typeparam>
/// <param name="propertyName">(Optional) The name of the property
/// that changed.</param>
/// <param name="setField">Action to execute to set the
/// field's value.</param>
/// <param name="oldValue">The current value of the field.</param>
/// <param name="newValue">The property's value after the change
/// occured.</param>
/// <returns>True if the PropertyChanged event has been raised,
/// false otherwise. The event is not raised if the old
/// value is equal to the new value.</returns>
protected bool Set<T>(
    string propertyName,
    Action<T> setField,
    T oldValue,
    T newValue)
{
    if (EqualityComparer<T>.Default.Equals(oldValue, newValue))
    {
        return false;
    }
    setField(newValue);
    RaisePropertyChanged(propertyName);
    return true;
}