/// <summary>
/// Returns all concrete types that are located in the supplied <paramref name="assemblies"/>
/// and implement or inherit from the supplied <paramref name="serviceType"/> and match the specified
/// <paramref name="options."/>. <paramref name="serviceType"/> can be an open-generic type.
/// </summary>
/// <remarks>
/// Use this method when you need influence the types that are registered using
/// <see cref="Register(System.Type, IEnumerable{System.Reflection.Assembly})">Register</see>.
/// The <b>Register</b> overloads that take a collection of <see cref="Assembly"/>
/// objects use this method internally to get the list of types that need to be registered. Instead of
/// calling such overload, you can call an overload that takes a list of <see cref="System.Type"/> objects
/// and pass in a filtered result from this <b>GetTypesToRegister</b> method.
/// <code lang="cs"><![CDATA[
/// var container = new Container();
///
/// var assemblies = new[] { typeof(ICommandHandler<>).Assembly };
/// var options = new TypesToRegisterOptions { IncludeGenericTypeDefinitions: true };
/// var types = container.GetTypesToRegister(typeof(ICommandHandler<>), assemblies, options)
/// .Where(type => !type.IsPublic);
///
/// container.Register(typeof(ICommandHandler<>), types);
/// ]]></code>
/// This example calls the <b>GetTypesToRegister</b> method to request a list of concrete implementations
/// of the <b>ICommandHandler<T></b> interface from the assembly of that interface. After that
/// all internal types are filtered out. This list is supplied to the
/// <see cref="Container.Register(System.Type,IEnumerable{System.Type})">Register(Type, IEnumerable<Type>)</see>
/// overload to finish the registration.
/// </remarks>
/// <param name="serviceType">The base type or interface to find derived types for. This can be both
/// a non-generic and open-generic type.</param>
/// <param name="assemblies">A list of assemblies that will be searched.</param>
/// <param name="options">The options.</param>
/// <returns>A collection of types.</returns>
/// <exception cref="ArgumentNullException">Thrown when one of the arguments contain a null reference
/// (Nothing in VB).</exception>
public IEnumerable <Type> GetTypesToRegister(Type serviceType, IEnumerable <Assembly> assemblies,
TypesToRegisterOptions options)
{
Requires.IsNotNull(serviceType, nameof(serviceType));
Requires.IsNotNull(assemblies, nameof(assemblies));
Requires.IsNotNull(options, nameof(options));
Requires.IsNotPartiallyClosed(serviceType, nameof(serviceType));
var types =
from assembly in assemblies.Distinct()
where !assembly.IsDynamic
from type in GetTypesFromAssembly(assembly)
where Helpers.IsConcreteType(type)
where options.IncludeGenericTypeDefinitions || !type.Info().IsGenericTypeDefinition
where Helpers.ServiceIsAssignableFromImplementation(serviceType, type)
let ctor = this.SelectImplementationTypeConstructorOrNull(serviceType, type)
where ctor == null || options.IncludeDecorators || !Helpers.IsDecorator(serviceType, ctor)
where ctor == null || options.IncludeComposites || !Helpers.IsComposite(serviceType, ctor)
select type;
return(types.ToArray());
}