What is Autowiring in DI Containers?

Question

C++ / C#

I began to study the structure of DI containers in general and in particular for C ++. After reviewing a number of implementations, I chose Hypodermic for myself. In general, using Unit tests, I figured out how to work with the library, but I didn’t quite understand about Autowiring. What it is?
PS I am attaching the text of two Unit-tests with the problem in question.

BOOST_AUTO_TEST_CASE(autowired_registration_follows_the_usual_registration_rules)
{
    // Arrange
    ContainerBuilder c;

    // Act
    c.autowireType< ServiceA >().as< IServiceA >();
    c.autowireType< ServiceB >().singleInstance();

    // Assert
    auto container = c.build();

    auto serviceB = container->resolve< ServiceB >();
    auto nullServiceB = container->resolve< IServiceB >();

    BOOST_CHECK(serviceB != nullptr);
    BOOST_CHECK(nullServiceB == nullptr);
    BOOST_CHECK(serviceB == container->resolve< ServiceB >());
}

BOOST_AUTO_TEST_CASE(autowired_registration_can_resolve_all_services)
{
    // Arrange
    ContainerBuilder c;
    c.autowireType< ServiceA >().as< IServiceA >().as< IRunWithScissors >();

    c.autowireType< ServiceB >().as< IServiceB >();
    c.autowireType< ServiceRunningWithScissors >().as< IServiceB >();

    c.autowireType< ServiceBController >();

    auto container = c.build();

    // Act
    auto serviceBController = container->resolve< ServiceBController >();

    // Assert
    BOOST_CHECK(serviceBController != nullptr);
}

Answer 1

Autowiring - autowiring. That is, the container itself, based on types, tries to guess who depends on who. You don't need to explicitly list all dependencies.