更新数组时出错

我有一个组件：

import { Component, OnInit } from '@angular/core';
import { PostService } from '../shared/services/post.service';
import { CreatePost } from '../shared/model/post.model';
import { Router } from '@angular/router';

@Component({
selector: 'app-post',
templateUrl: './post.component.html',
styleUrls: ['./post.component.css']
})
export class PostComponent implements OnInit {

 confirmPost:CreatePost[] = [];
 unconfirmPost:CreatePost[] = [];
searchPost = '';

 constructor(
   private postService: PostService,
  private router: Router
  ) { }

  ngOnInit() {
  this.postService.getPosts()
  .subscribe((post: CreatePost[])=>{
    this.confirmPost = post.filter(p => p.confirm === true).reverse();
    this.unconfirmPost = post.filter(p => p.confirm === false);
  });
}

 watchPost(post:CreatePost){
   this.router.navigate(['/system/post', post.id],{queryParams: post});
 }

 confirmePost(post:CreatePost){
  post.confirm = true;
  this.postService.updatePost(post)
   .subscribe((poste:CreatePost[]) => {
   this.confirmPost = this.confirmPost.unshift(poste);
  });
  }
 }

CreatePost 模型：

export class CreatePost{
  constructor(
    public data: any,
    public category: string,
    public user: string,
    public title: string,
    public text: string,
    public like: number,
    public watch: number,
    public confirm: boolean,
    public id?: number
  ){}
}

当我尝试更新数组 this.confirmPost = this.confirmPost.unshift(poste); 我收到一个错误：

ERROR in src/app/system/post/post.component.ts(39,51): error TS2345: Argument of type 'CreatePost[]' is not assignable to parameter of type 'CreatePost'.
  Type 'CreatePost[]' is missing the following properties from type 'CreatePost': data, category, user, title, and 4 more.