Implement service locator

Dalamud/IoC/Internal/InterfaceVersionAttribute.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace Dalamud.IoC.Internal
+{
+    /// <summary>
+    /// This attribute represents the current version of a module that is loaded in the Service Locator.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface)]
+    internal class InterfaceVersionAttribute : Attribute
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="InterfaceVersionAttribute"/> class.
+        /// </summary>
+        /// <param name="version">The current version.</param>
+        public InterfaceVersionAttribute(string version)
+        {
+            this.Version = new(version);
+        }
+
+        /// <summary>
+        /// Gets the service version.
+        /// </summary>
+        public Version Version { get; }
+    }
+}

Dalamud/IoC/PluginInterfaceAttribute.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace Dalamud.IoC
+{
+    /// <summary>
+    /// This attribute indicates whether the decorated class should be exposed to plugins via IoC.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class)]
+    public class PluginInterfaceAttribute : Attribute
+    {
+    }
+}

Dalamud/IoC/RequiredVersionAttribute.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace Dalamud.IoC
+{
+    /// <summary>
+    /// This attribute indicates the version of a service module that is required for the plugin to load.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Parameter)]
+    public class RequiredVersionAttribute : Attribute
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RequiredVersionAttribute"/> class.
+        /// </summary>
+        /// <param name="version">The required version.</param>
+        public RequiredVersionAttribute(string version)
+        {
+            this.Version = new(version);
+        }
+
+        /// <summary>
+        /// Gets the required version.
+        /// </summary>
+        public Version Version { get; }
+    }
+}