lib/ffi/data_converter.rb



#
# Copyright (C) 2008-2010 Wayne Meissner
#
# This file is part of ruby-ffi.
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
# * Neither the name of the Ruby FFI project nor the names of its contributors
#   may be used to endorse or promote products derived from this software
#   without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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module FFI
  # This module is used to extend somes classes and give then a common API.
  #
  # Most of methods defined here must be overriden.
  module DataConverter
    # Get native type.
    #
    # @overload native_type(type)
    #  @param [String, Symbol, Type] type
    #  @return [Type]
    #  Get native type from +type+.
    #
    # @overload native_type
    #  @raise {NotImplementedError} This method must be overriden.
    def native_type(type = nil)
      if type
        @native_type = FFI.find_type(type)
      else
        native_type = @native_type
        unless native_type
          raise NotImplementedError, 'native_type method not overridden and no native_type set'
        end
        native_type
      end
    end

    # Convert to a native type.
    def to_native(value, ctx)
      value
    end

    # Convert from a native type.
    def from_native(value, ctx)
      value
    end
  end
end