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/*
* Copyright (c) 2022. Deutsche Telekom AG
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* SPDX-License-Identifier: Apache-2.0
*/
import { Pipe, PipeTransform } from '@angular/core';
export type TypeGuard<A, B extends A> = (a: A) => a is B;
// https://github.com/angular/angular/issues/34522#issuecomment-762973301
@Pipe({
name: 'guardType',
})
export class GuardTypePipe implements PipeTransform {
transform<A, B extends A>(value: A, typeGuard: TypeGuard<A, B>): B | undefined {
return typeGuard(value) ? value : undefined;
}
}
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