CStruct:Examples:First sample

    # CStruct Examples
    require 'cstruct'

    # example:
    # struct Point in C\C++        (32-bit platform):
    #
    # struct Point
    # {
    #    int x;
    #    int y;
    # };

    # struct Point in Ruby:
    class Point < CStruct
      int32:x
      int32:y
    end

    # create a Point's instance
    point   = Point.new

    # assign like as C language
    point.x = 10
    point.y = 20

    puts "point.x = #{point.x},point.y = #{point.y}"

    # struct PointF in C\C++        (32-bit platform):
    #
    # struct PointF
    # {
    #    double x;
    #    double y;
    # };

    # struct PointF in Ruby:
    class PointF < CStruct
      double:x
      double:y
    end

    # create a PointF's instance
    # use 'block' to initialize the fields
    point2   = PointF.new do |st|
            st.x = 10.56
            st.y = 20.78
    end

    puts "sizeof(PointF) = #{PointF.size}"
    puts "point2.x = #{point2.x},point2.y = #{point2.y}"