C++ перегрузка оператора сложения двух классов. Не находит походящий конструктор

Ошибка:

// Содержание файла .h

class MemoryDevice {

private:
    static int count;

    string name;
    unsigned int ID;
    unsigned int MaxMemorySize;
    unsigned int CurrentMemoryByte;
    unsigned int FreeMemoryByte;
    char* Memory;
public:
    string getName();
    unsigned int getMaxSize();

    MemoryDevice();
    MemoryDevice(std::string, unsigned int);
    ~MemoryDevice();

    MemoryDevice operator + (MemoryDevice);

};
// Содержание файла .cpp

MemoryDevice::MemoryDevice(std::string name, unsigned int MaxMemory = 1024) {
    this->name = name;
    this->ID = count;
    this->MaxMemorySize = MaxMemory;
    this->FreeMemoryByte = MaxMemory;
    this->Memory = new char[this->MaxMemorySize];
    for (int i = 0; i < MaxMemory; i++)
    {
        Memory[i] = -1;
    }
    count++;
};


string MemoryDevice::getName() {
    return this->name;
}
unsigned int MemoryDevice::getMaxSize() {
    return this->MaxMemorySize;
};

MemoryDevice MemoryDevice::operator + (MemoryDevice c1) {

     return MemoryDevice(c1.getName() + " " + this->getName(), (unsigned int)(c1.getMaxSize() + this->getMaxSize()));
};