public struct SomeStruct
{
    public SomeStruct(String stringProperty, Int32 intProperty)
    {
        this.StringProperty = stringProperty;
        this.IntProperty = intProperty;
    }

    public String StringProperty { get; set; }
    public Int32 IntProperty { get; set; }
}

public SomeStruct(String stringProperty, Int32 intProperty) : this()
{
    this.StringProperty = stringProperty;
    this.IntProperty = intProperty;
}

myFoo.f2 = someValue;

myFoo = new Foo(myFoo.f1, someValue);