initial commit

src/core/common/types.ts

@@ -0,0 +1,13 @@
+export type Diff<T extends keyof any, U extends keyof any> = ({ [P in T]: P } &
+    { [P in U]: never } & { [x: string]: never })[T];
+
+export type Omit<U, K extends keyof U> = Pick<U, Diff<keyof U, K>>;
+
+export type Overwrite<T, U> = Pick<T, Diff<keyof T, keyof U>> & U;
+
+export type Sub<T, U> = Pick<T, Diff<keyof T, keyof U>>;
+
+/**
+ * Make all properties in T writeable
+ */
+export type Writeable<T> = { -readonly [P in keyof T]: T[P] };