Add StandardUtils

mirai-core-api/src/commonMain/kotlin/utils/StandardUtils.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2019-2020 Mamoe Technologies and contributors.
+ *
+ *  此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ *  Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ *
+ *  https://github.com/mamoe/mirai/blob/master/LICENSE
+ */
+
+@file:JvmName("MiraiUtils")
+
+package net.mamoe.mirai.utils
+
+@PublishedApi
+internal inline fun <reified T> Any?.cast(): T = this as T
+
+@PublishedApi
+internal inline fun <reified T> Any?.safeCast(): T? = this as? T
+
+@PublishedApi
+internal inline fun <reified T> Any?.castOrNull(): T? = this as? T