diff --git a/ffi/src/main/kotlin/gay/pizza/pork/ffi/FfiPrimitiveType.kt b/ffi/src/main/kotlin/gay/pizza/pork/ffi/FfiPrimitiveType.kt
new file mode 100644
index 0000000..3464aea
--- /dev/null
+++ b/ffi/src/main/kotlin/gay/pizza/pork/ffi/FfiPrimitiveType.kt
@@ -0,0 +1,30 @@
+package gay.pizza.pork.ffi
+
+import gay.pizza.pork.evaluator.None
+
+enum class FfiPrimitiveType(
+  val id: kotlin.String,
+  override val size: kotlin.Int,
+  val numberConvert: (Number.() -> Number)? = null,
+  val nullableConversion: (Any?.() -> Any)? = null,
+  val notNullConversion: (Any.() -> Any)? = null
+) : FfiType {
+  Byte("byte", 1, numberConvert = { toByte() }),
+  UnsignedByte("unsigned byte", 1, numberConvert = { toByte()}),
+  Short("short", 2, numberConvert = { toShort() }),
+  UnsignedShort("unsigned short", 2, numberConvert = { toShort() }),
+  Int("int", 4, numberConvert = { toInt() }),
+  UnsignedInt("unsigned int", 4, numberConvert = { toInt() }),
+  Float("float", 4, numberConvert = { toFloat() }),
+  Long("long", 8, numberConvert = { toLong() }),
+  UnsignedLong("unsigned long", 8, numberConvert = { toLong() }),
+  Double("double", 8, numberConvert = { toDouble() }),
+  String("char*", 8, nullableConversion = { toString() }),
+  Pointer("void*", 8, nullableConversion = {
+    if (this is kotlin.Long) {
+      com.sun.jna.Pointer(this)
+    } else if (this == None) {
+      com.sun.jna.Pointer.NULL
+    } else this as com.sun.jna.Pointer
+  })
+}
diff --git a/ffi/src/main/kotlin/gay/pizza/pork/ffi/FfiStruct.kt b/ffi/src/main/kotlin/gay/pizza/pork/ffi/FfiStruct.kt
new file mode 100644
index 0000000..58109fe
--- /dev/null
+++ b/ffi/src/main/kotlin/gay/pizza/pork/ffi/FfiStruct.kt
@@ -0,0 +1,14 @@
+package gay.pizza.pork.ffi
+
+class FfiStruct : FfiType {
+  private val fields = mutableListOf<FfiStructField>()
+
+  data class FfiStructField(val name: String, val type: FfiType)
+
+  fun add(field: String, type: FfiType) {
+    fields.add(FfiStructField(field, type))
+  }
+
+  override val size: Int
+    get() = fields.sumOf { it.type.size }
+}
diff --git a/ffi/src/main/kotlin/gay/pizza/pork/ffi/FfiType.kt b/ffi/src/main/kotlin/gay/pizza/pork/ffi/FfiType.kt
new file mode 100644
index 0000000..55ab5a7
--- /dev/null
+++ b/ffi/src/main/kotlin/gay/pizza/pork/ffi/FfiType.kt
@@ -0,0 +1,5 @@
+package gay.pizza.pork.ffi
+
+interface FfiType {
+  val size: Int
+}
diff --git a/ffi/src/main/kotlin/gay/pizza/pork/ffi/JnaNativeProvider.kt b/ffi/src/main/kotlin/gay/pizza/pork/ffi/JnaNativeProvider.kt
index 7953c4f..77382e4 100644
--- a/ffi/src/main/kotlin/gay/pizza/pork/ffi/JnaNativeProvider.kt
+++ b/ffi/src/main/kotlin/gay/pizza/pork/ffi/JnaNativeProvider.kt
@@ -2,7 +2,6 @@ package gay.pizza.pork.ffi
 
 import com.sun.jna.Function
 import com.sun.jna.NativeLibrary
-import com.sun.jna.Pointer
 import gay.pizza.pork.ast.ArgumentSpec
 import gay.pizza.pork.evaluator.CallableFunction
 import gay.pizza.pork.evaluator.NativeProvider
@@ -48,24 +47,23 @@ class JnaNativeProvider : NativeProvider {
     else -> type
   }
 
-  private fun convert(type: String, value: Any?): Any? = when (rewriteType(type)) {
-    "short" -> numberConvert(type, value) { toShort() }
-    "unsigned short" -> numberConvert(type, value) { toShort() }
-    "int" -> numberConvert(type, value) { toInt() }
-    "unsigned int" -> numberConvert(type, value) { toInt() }
-    "long" -> numberConvert(type, value) { toLong() }
-    "unsigned long" -> numberConvert(type, value) { toLong() }
-    "double" -> numberConvert(type, value) { toDouble() }
-    "float" -> numberConvert(type, value) { toFloat() }
-    "char*" -> notNullConvert(type, value) { toString() }
-    "void*" -> nullableConvert(value) {
-      if (value is Long) {
-        Pointer(value)
-      } else {
-        value as Pointer
-      }
+  private fun convert(type: String, value: Any?): Any? {
+    val rewritten = rewriteType(type)
+    val primitive = FfiPrimitiveType.entries.firstOrNull { it.id == rewritten }
+      ?: throw RuntimeException("Unsupported ffi type: $type")
+    if (primitive.numberConvert != null) {
+      return numberConvert(type, value, primitive.numberConvert)
     }
-    else -> throw RuntimeException("Unsupported ffi type: $type")
+
+    if (primitive.notNullConversion != null) {
+      return notNullConvert(type, value, primitive.notNullConversion)
+    }
+
+    if (primitive.nullableConversion != null) {
+      return nullableConvert(value, primitive.nullableConversion)
+    }
+
+    return value
   }
 
   private fun <T> notNullConvert(type: String, value: Any?, into: Any.() -> T): T {
diff --git a/gradle.properties b/gradle.properties
index 2b17698..3135fdb 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,2 +1,3 @@
 org.gradle.warning.mode=none
 kotlin.stdlib.default.dependency=false
+kotlin.experimental.tryK2=true