1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16#pragma once
17
18#include <stdio.h>
19#include <stdarg.h>
20
21#include <string>
22
23class Result {
24public:
25    static Result success() {
26        return Result(true);
27    }
28    // Construct a result indicating an error.
29    static Result error(std::string message) {
30        return Result(message);
31    }
32    static Result error(const char* format, ...) {
33        char buffer[1024];
34        va_list args;
35        va_start(args, format);
36        vsnprintf(buffer, sizeof(buffer), format, args);
37        va_end(args);
38        buffer[sizeof(buffer) - 1] = '\0';
39        return Result(std::string(buffer));
40    }
41
42    bool isSuccess() const { return mSuccess; }
43    bool operator!() const { return !mSuccess; }
44
45    const char* c_str() const { return mMessage.c_str(); }
46private:
47    explicit Result(bool success) : mSuccess(success) { }
48    explicit Result(std::string message)
49        : mMessage(message), mSuccess(false) {
50    }
51    std::string mMessage;
52    bool mSuccess;
53};
54
55