Method: FFI::Library#callback

Defined in:

lib/ffi/library.rb

#callback(name, params, ret) ⇒ FFI::CallbackInfo #callback(params, ret) ⇒ FFI::CallbackInfo

Overloads:

• #callback(name, params, ret) ⇒ FFI::CallbackInfo

  Parameters:

  • name —

    callback name to add to type map

  • params (Array) —

    array of parameters’ types

  • ret (DataConverter, Struct, Symbol, Type) —

    callback return type

• #callback(params, ret) ⇒ FFI::CallbackInfo

  Parameters:

  • params (Array) —

    array of parameters’ types

  • ret (DataConverter, Struct, Symbol, Type) —

    callback return type

Returns:

• (FFI::CallbackInfo)

Raises:

• (ArgumentError)

# File 'lib/ffi/library.rb', line 330

def callback(*args)
  raise ArgumentError, "wrong number of arguments" if args.length < 2 || args.length > 3
  name, params, ret = if args.length == 3
    args
  else
    [ nil, args[0], args[1] ]
  end

  native_params = params.map { |e| find_type(e) }
  raise ArgumentError, "callbacks cannot have variadic parameters" if native_params.include?(FFI::Type::VARARGS)
  options = Hash.new
  options[:convention] = ffi_convention
  options[:enums] = @ffi_enums if defined?(@ffi_enums)
  ret_type = find_type(ret)
  if ret_type == Type::STRING
    raise TypeError, ":string is not allowed as return type of callbacks"
  end
  cb = FFI::CallbackInfo.new(ret_type, native_params, options)

  # Add to the symbol -> type map (unless there was no name)
  unless name.nil?
    typedef cb, name
  end

  cb
end