feat(core): abstract OnlySubType type-level function

typp-js · Feb 27, 2024 · ad53ea4 · ad53ea4
1 parent f3ab2f2
commit ad53ea4
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
@@ -58,6 +58,10 @@ export type IsAnySubType<T, U> = IsTrue<
   U extends infer UI ? IsSubType<T, UI> : never
 >
 
+export type OnlySubType<T, U> = Not<IsWhat<T, U>> extends true
+  ? T extends U ? true : false
+  : false
+
 export type Includes<
   T extends readonly any[],
   U extends readonly any[]