如何在Swift中使用JSON编码器的泛型

我使用JSON Placeholder post api在SWIFT中使用泛型和结果类型发出HTTP POST请求.以下是我用于请求和响应的可编码 struct .对于此接口，响应和请求都相同.

enum AddPostModel{
    struct AddPostRequest: Codable{
        let title: String
        let body: String
        let userId: String
        let id: String
    }
    struct AddPostResponse: Codable{
        let title: String
        let body: String
        let userId: String
        let id: String
    }
}

以下是我使用URLSession异步/等待、泛型和结果类型的POST请求代码.

func sendPostRequest<T: Codable>(url: String,responseType: T.Type,params: T) async -> Result<T,Error>{
        do{
            let session = URLSession(configuration: .default)
            guard let url = URL(string: url) else{return .failure(HTTPError.invalidUrl) }
            var request = URLRequest(url: url)
            request.httpMethod = HTTPMethods.POST.method
            
            
            let jsonData = try JSONEncoder().encode(params)
            request.httpBody = jsonData
            
            let (data,response) = try await session.data(for: request)
            guard let urlResponse = response as? HTTPURLResponse , (200...299).contains(urlResponse.statusCode)
              else{ return .failure(HTTPError.failedResponse)}
            
            
            let jsonResponse = try JSONDecoder().decode(responseType.self, from: data)
            return .success(jsonResponse)
            
        }
        catch{
            return .failure(error)
        }
    }

在这里，我调用Post方法

 func addPost(params: AddPostModel.AddPostRequest) async -> Result<AddPostModel.AddPostResponse,Error>{
        
        return await service.sendPostRequest(url: Constant.BASE_URL + "/" + HomeEndPoints.posts.path, responseType: AddPostModel.AddPostResponse.self, params: params)
    }

当我try 构建时，在sendPostRequest方法的params参数中得到以下错误

无法将类型AddPostModel.AddPostRequest的值转换为预期的参数类型AddPostModel.AddPostResponse