feat: introduce UnwrapOpaque type

index.d.ts

@@ -18,7 +18,7 @@ export {PartialDeep} from './source/partial-deep';
 export {ReadonlyDeep} from './source/readonly-deep';
 export {LiteralUnion} from './source/literal-union';
 export {Promisable} from './source/promisable';
-export {Opaque} from './source/opaque';
+export {Opaque, DeOpaque} from './source/opaque';
 export {InvariantOf} from './source/invariant-of';
 export {SetOptional} from './source/set-optional';
 export {SetRequired} from './source/set-required';

source/opaque.d.ts

@@ -72,3 +72,5 @@ type Person = {
 @category Type
 */
 export type Opaque<Type, Token = unknown> = Type & Tagged<Token>;
+
+export type DeOpaque<Type> = Omit<Type, keyof Tagged<unknown>>;

test-d/opaque.ts

@@ -1,5 +1,5 @@
-import {expectAssignable, expectError} from 'tsd';
-import type {Opaque} from '../index';
+import {expectAssignable, expectError, expectNotType} from 'tsd';
+import type {Opaque, DeOpaque} from '../index';
 
 type Value = Opaque<number, 'Value'>;
 
@@ -38,3 +38,11 @@ const johnsId = '7dd4a16e-d5ee-454c-b1d0-71e23d9fa70b' as UUID;
 // @ts-expect-error
 const userJohn = userEntities[johnsId]; // eslint-disable-line @typescript-eslint/no-unused-vars
 /// expectType<Foo>(userJohn);
+
+// Remove tag from opaque value
+// note: this will simply return number as type
+type PlainValue = DeOpaque<Value>;
+expectAssignable<PlainValue>(123);
+
+const plainValue: PlainValue = 123 as PlainValue;
+expectNotType<Value>(plainValue);