realloc() & ARC

Question

如何重写以下实用程序类以获得特定类型的所有类字符串值--使用目标-c运行时函数，如下所示？

ARC文档明确指出，应当避免realloc，我还在这一行中得到以下编译器错误：

classList = realloc(classList, sizeof(Class) * numClasses);

“非目标-C指针类型'void *‘到'__unsafe_unretained Class *’的隐式转换是不允许的

下面的代码是对可以找到here的原始文章的引用。

+ (NSArray *)classStringsForClassesOfType:(Class)filterType {

    int numClasses = 0, newNumClasses = objc_getClassList(NULL, 0);
    Class *classList = NULL;

    while (numClasses < newNumClasses) {
        numClasses = newNumClasses;
        classList = realloc(classList, sizeof(Class) * numClasses);
        newNumClasses = objc_getClassList(classList, numClasses);
    }

    NSMutableArray *classesArray = [NSMutableArray array];

    for (int i = 0; i < numClasses; i++) {
        Class superClass = classList[i];
        do {
            superClass = class_getSuperclass(superClass);
            if (superClass == filterType) {
                [classesArray addObject:NSStringFromClass(classList[i])];
                break;
            }           
        } while (superClass);       
    }

    free(classList);

    return classesArray;
}

你的帮助将不胜感激。

Answer 1

弧强制您对您的内存管理更加明确。在这种情况下，只需要显式地强制转换realloc的输出：

classList = (Class *)realloc(classList, sizeof(Class) * numClasses);