Why use universal and neon options for functions?

Question

I study the code of some different libraries and notice that some of them will provide equivalent general and non-general functions in one class.

One example is the IServiceLocator interface of a common project maintenance locator :

public interface IServiceLocator
{
    object GetInstance(Type serviceType);
    object GetInstance(Type serviceType, string key);
    IEnumerable<object> GetAllInstances(Type serviceType);

    TService GetInstance<TService>();
    TService GetInstance<TService>(string key);
    IEnumerable<TService> GetAllInstances<TService>();

}

The impression I get is that it maximizes availability, possibly from COM. In the absence of these problems, this seems like redundant code. Is there something I am missing?

Answer 1

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Answer 2

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Answer 3

The reason is that non-Generic will use the implied generics, checking its type so you don't have to mention the type.