c++ - 我收到警告控制到达非无效函数的结尾

Question

我的程序似乎在 Visual Studio 中运行良好，但是当我在 GCC 中运行它时，它给了我一个名为的编译错误

Book.cpp: In member function ‘sdds::Book& sdds::Book::addChapter(const char*, int)’:
Book.cpp:64:5: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

我不知道该怎么做，有人可以帮忙告诉我应该改变什么吗？这是我收到错误的文件。函数是第一章的add。我使用的返回语句是“return *this”，但这似乎不起作用。我的代码在 Visual Studio 中编译得很好，但在 GCC 中编译得不好。

namespace sdds
{
    Book::Book(const char* book_name, int noOfChapters, const Chapter* chapters)
    {
        // initially assume that everything is valid
        this->isValid = true;
        this->book_name = nullptr;
        this->chapters = nullptr;
        this->noOfChapters = 0;
        int length = (book_name != nullptr ? strlen(book_name) : 0);
        // check if book_name is valid
        if (length < 1)             this->isValid = false;
        if (noOfChapters < 1)       this->isValid = false;
        // check if all chapters are valid
        for (int i = 0; i < noOfChapters; i++)
            if (!chapters[i].isValidChapter())
                this->isValid = false;
        // check if valid information is provided to create book
        if (this->isValid) {
            // create a string on heap for book_name
            this->book_name = new char[length + 1];
            //copy the elements
            strcpy(this->book_name, book_name);
            // allocate memory for chapters
            this->chapters = new Chapter[noOfChapters];
            // create copies of chapters
            for (int i = 0; i < noOfChapters; i++)
                this->chapters[this->noOfChapters++] = chapters[i];
        }
    }
    bool Book::isEmpty() const
    {
        // check if book is empty or invalid
        return (isValid || this->noOfChapters == 0);
    }
    Book& Book::addChapter(const char* chapter_name, int noOfPages)
    {
        // create a new chapter
        Chapter chapter(chapter_name, noOfPages);
        // check if chapter is valid
        if (chapter.isValidChapter()) {
            // add the chapter to list of chapters
            // create a new list of chapters
            Chapter* chapters = new Chapter[this->noOfChapters + 1];
            // copy chapters to new array
            for (int i = 0; i < this->noOfChapters; i++)
                chapters[i] = this->chapters[i];
            // add the last chapter
            chapters[this->noOfChapters++] = chapter;
            // delete the old list of chapters
            delete this->chapters;
            // update the list of chapters
            this->chapters = chapters;
            return *this;
        }
    }
    void Book::display() const
    {
        // check if book is valid3
        if (!isValid) {
            std::cout << "Invalid Book object";
            std::cout << std::endl;
        }
        else {
            std::cout << "Book Name: " << this->book_name << std::endl;
            std::cout << "No of Chapters: " << this->noOfChapters << std::endl;
            std::cout.width(50);
            std::cout << std::left;
            std::cout.fill(' ');
            std::cout << "Chapter name" << " ";
            std::cout << "Pages";
            std::cout << std::endl;
            for (int i = 0; i < noOfChapters; i++) {
                // display the ith chapter
                chapters[i].display();
                std::cout << std::endl;
            }
        }
    }
    Book::~Book()
    {
        // delete memory allocaed to book_name and chapters
        if (book_name != nullptr)   delete book_name;
        if (chapters != nullptr)    delete chapters;
    }


}

标签： c++