Question

我有以下代码来覆盖＆lt;＆lt;运营商
到目前为止，我已将错误定位为++它。每当涉及到这段代码时，我的程序都会崩溃（SIGTERM）。

ostream& operator<<(ostream& os, const Kooi& kooi) {
    map<int, Dier*>::const_iterator it;
    for (it = kooi.de_dieren->begin(); it != kooi.de_dieren->end(); ++it) {
        os << it->second << endl;
    }
}

return os;

编辑：Kooi类的完整头文件：

#ifndef kooi_H
#define kooi_H 1.3


#include <string>   // voor: std::string
#include <iostream> // voor: std::ostream
#include <map>      // voor: std::map<K,V>
#include <iterator> // voor: next
#include "Dier.h"   // voor: class Dier


/** @class Kooi Kooi.h
 * A cage class to hold animals of the same type.
 */
class Kooi
{
        // The Kooi output operator to print the cage.
        // It also prints any animals within.
        friend std::ostream& operator<<(std::ostream&, const Kooi&);

    private:
        std::string      de_diersoort;  // the animal category
        std::map<int, Dier*>    *de_dieren;     // the animal container

    public:
        /// Construct a cage for the given type of animals
        /// @param diersoort    The animal category
        ///     @pre diersoort must be a non-empty string
        Kooi(const std::string& diersoort);

        /// Destroy a cage, any animals within should also be destroyed
        ~Kooi();

        /// Return the animal category of this cage
        /// @return The animal category
        inline const std::string&  getSoort() const {
            return de_diersoort;
        }

        /// Add an animal to this cage
        /// @param  nummer   The unique number of the animal
        ///     @pre That animal number may not already exist in this cage
        /// @param  dier     The animal to be added
        ///     @pre The type of that animal must match with the type of this cage
        void     addDier(int nummer, Dier *dier);

        /// Lookup an animal in this cage
        /// @param  nummer  The number of the animal sought
        ///     @pre That animal number must be >= 0
        /// @returns 0 when the animal is not in this cage
        Dier    *getDier(int nummer) const;

        /// Remove an animal from this cage
        /// @param  nummer  The number of the animal to be removed
        ///     @pre That animal number must exist in this cage
        void     erase(int nummer);

        /// Tell the number of animals in this cage
        ///  (used e.g.to calculate the salary of a animalkeeper)
        inline int      size() const {
            return de_dieren->size();
        }

        // =====================================
        /// Save this cage (and the animals) in a file
        void saveFile(std::ostream& out) const;
};


/// Kooi output operator (prints both the cage and all animals within)
std::ostream& operator<<(std::ostream& os, const Kooi& kooi);


#endif  /*kooi*/

// vim:sw=4:ai:aw:ts=4:

此外，由于某种原因，我100％肯定该程序在++it崩溃。

请注意，此代码是学校作业的一部分，因此我们不应该过多地使用代码。此作业的范围仅为kooi.cc文件

C ++试图迭代一个常量类的映射？

0 个答案: