gem_platforms

# File lib/rubygems/request_set/gem_dependency_api.rb, line 487
  def gem_platforms options # :nodoc:
    platform_names = Array(options.delete :platform)
    platform_names.concat Array(options.delete :platforms)
    platform_names.concat @current_platforms if @current_platforms

    return true if platform_names.empty?

    platform_names.any? do |platform_name|
      raise ArgumentError, "unknown platform #{platform_name.inspect}" unless
        platform = PLATFORM_MAP[platform_name]

      next false unless Gem::Platform.match platform

      if engines = ENGINE_MAP[platform_name] then
        next false unless engines.include? Gem.ruby_engine
      end

      case WINDOWS[platform_name]
      when :only then
        next false unless Gem.win_platform?
      when :never then
        next false if Gem.win_platform?
      end

      VERSION_MAP[platform_name].satisfied_by? Gem.ruby_version
    end
  end