Enchancement suggestion for argparse: intuit type from default

[Roy Smith]

Using argparse, if I write:

    parser.add_argument('--foo', default=100)

it seems like it should be able to intuit that the type of foo should
be int (i.e. type(default)) without my having to write:

    parser.add_argument('--foo', type=int, default=100)

Does this seem like a reasonable enhancement to argparse?