src/main/kotlin/org/duckdns/davygora/matrix/storage/BooleanStorage.kt

@@ -2,7 +2,7 @@ package org.duckdns.davygora.matrix.storage
 
 @JvmInline
 value class BooleanStorage(
-    val data: BooleanArray,
+    override val data: BooleanArray,
 ) : MatrixStorage<Boolean> {
     override val size get() = data.size
 

src/main/kotlin/org/duckdns/davygora/matrix/storage/ByteStorage.kt

@@ -2,7 +2,7 @@ package org.duckdns.davygora.matrix.storage
 
 @JvmInline
 value class ByteStorage(
-    val data: ByteArray,
+    override val data: ByteArray,
 ) : MatrixStorage<Byte> {
     override val size get() = data.size
 

src/main/kotlin/org/duckdns/davygora/matrix/storage/CharStorage.kt

@@ -2,7 +2,7 @@ package org.duckdns.davygora.matrix.storage
 
 @JvmInline
 value class CharStorage(
-    val data: CharArray,
+    override val data: CharArray,
 ) : MatrixStorage<Char> {
     override val size get() = data.size
 

src/main/kotlin/org/duckdns/davygora/matrix/storage/DoubleStorage.kt

@@ -2,7 +2,7 @@ package org.duckdns.davygora.matrix.storage
 
 @JvmInline
 value class DoubleStorage(
-    val data: DoubleArray,
+    override val data: DoubleArray,
 ) : MatrixStorage<Double> {
     override val size get() = data.size
 

src/main/kotlin/org/duckdns/davygora/matrix/storage/FloatStorage.kt

@@ -2,7 +2,7 @@ package org.duckdns.davygora.matrix.storage
 
 @JvmInline
 value class FloatStorage(
-    val data: FloatArray,
+    override val data: FloatArray,
 ) : MatrixStorage<Float> {
     override val size get() = data.size
 

src/main/kotlin/org/duckdns/davygora/matrix/storage/IntStorage.kt

@@ -2,7 +2,7 @@ package org.duckdns.davygora.matrix.storage
 
 @JvmInline
 value class IntStorage(
-    val data: IntArray,
+    override val data: IntArray,
 ) : MatrixStorage<Int> {
     override val size get() = data.size
 

src/main/kotlin/org/duckdns/davygora/matrix/storage/LongStorage.kt

@@ -2,7 +2,7 @@ package org.duckdns.davygora.matrix.storage
 
 @JvmInline
 value class LongStorage(
-    val data: LongArray,
+    override val data: LongArray,
 ) : MatrixStorage<Long> {
     override val size get() = data.size
 

src/main/kotlin/org/duckdns/davygora/matrix/storage/MatrixStorage.kt

@@ -1,6 +1,8 @@
 package org.duckdns.davygora.matrix.storage
 
 sealed interface MatrixStorage<T> {
+    val data: Any
+
     val size: Int
 
     operator fun get(index: Int): T
@@ -12,8 +14,18 @@ sealed interface MatrixStorage<T> {
 }
 
 @Suppress("UNCHECKED_CAST")
-inline fun <reified T> List<T>.toMatrixStorage() =
+inline fun <reified T> List<T>.toMatrixStorage(): MatrixStorage<T> {
-    when (T::class) {
+    firstNotNullOfOrNull { it }
+
+    val elementClass =
+        firstOrNull()
+            ?.let { first -> first::class }
+            ?.takeIf { clazz ->
+                all { it == null || it::class == clazz }
+            }
+            ?: T::class
+
+    return when (elementClass) {
         Boolean::class -> (this as List<Boolean>).toBooleanArray().toMatrixStorage()
         Byte::class -> (this as List<Byte>).toByteArray().toMatrixStorage()
         Char::class -> (this as List<Char>).toCharArray().toMatrixStorage()
@@ -24,3 +36,4 @@ inline fun <reified T> List<T>.toMatrixStorage() =
         Short::class -> (this as List<Short>).toShortArray().toMatrixStorage()
         else -> this.toTypedArray().toMatrixStorage()
     } as MatrixStorage<T>
+}

src/main/kotlin/org/duckdns/davygora/matrix/storage/ObjectStorage.kt

@@ -2,7 +2,7 @@ package org.duckdns.davygora.matrix.storage
 
 @JvmInline
 value class ObjectStorage<T>(
-    val data: Array<T>,
+    override val data: Array<T>,
 ) : MatrixStorage<T> {
     override val size get() = data.size
 

src/main/kotlin/org/duckdns/davygora/matrix/storage/ShortStorage.kt

@@ -2,7 +2,7 @@ package org.duckdns.davygora.matrix.storage
 
 @JvmInline
 value class ShortStorage(
-    val data: ShortArray,
+    override val data: ShortArray,
 ) : MatrixStorage<Short> {
     override val size get() = data.size
 

src/test/kotlin/org/duckdns/davygora/matrix/storage/MatrixStorageTest.kt

@@ -0,0 +1,50 @@
+package org.duckdns.davygora.matrix.storage
+
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.datatest.withData
+import io.kotest.matchers.shouldBe
+import kotlin.reflect.KClass
+
+class MatrixStorageTest :
+    FunSpec({
+        val testCases: Map<String, Triple<List<*>, KClass<*>, KClass<*>>> =
+            mapOf(
+                "boolean" to Triple(listOf(true, false), BooleanStorage::class, BooleanArray::class),
+                "byte" to Triple((0..100).map { it.toByte() }, ByteStorage::class, ByteArray::class),
+                "char" to Triple(('a'..'z') + ('A'..'Z') + ('0'..'9'), CharStorage::class, CharArray::class),
+                "double" to Triple((0..100).map { it.toDouble() }, DoubleStorage::class, DoubleArray::class),
+                "float" to Triple((0..100).map { it.toFloat() }, FloatStorage::class, FloatArray::class),
+                "int" to Triple((0..100).map { it }, IntStorage::class, IntArray::class),
+                "long" to Triple((0..100).map { it.toLong() }, LongStorage::class, LongArray::class),
+                "short" to Triple((0..100).map { it.toShort() }, ShortStorage::class, ShortArray::class),
+                "object" to Triple((0..100).map { first -> Pair(first, (0..100).random()) }, ObjectStorage::class, Array<Any>::class),
+            )
+
+        context("list of elements of a given type should produce corresponding storage, size, get and set should work") {
+            withData(
+                testCases,
+            ) { (allowedValues, storageClass, dataClass) ->
+
+                // Arrange
+
+                val size = (10..1000).random()
+                val list = List(size) { allowedValues.random() }
+                val newList = List(size) { allowedValues.random() }
+
+                // Act
+
+                val storage = list.toMatrixStorage()
+
+                // Assert
+
+                storage::class shouldBe storageClass
+                storage.data::class shouldBe dataClass
+
+                storage.size shouldBe size
+                list.forEachIndexed { index, value -> storage[index] shouldBe value }
+
+                newList.forEachIndexed { index, value -> storage[index] = value }
+                newList.forEachIndexed { index, value -> storage[index] shouldBe value }
+            }
+        }
+    })