MSDN page for developers有以下代码片段：
// Move constructor.
MemoryBlock(MemoryBlock&& other) : _data(nullptr),_length(0)
{
std::cout << "In MemoryBlock(MemoryBlock&&). length = "
<< other._length << ". Moving resource." << std::endl;
// Copy the data pointer and its length from source object.
_data = other._data; // Assginment 1
_length = other._length; // Assignment 2
// Release the data pointer from the source object so that
// the destructor does not free the memory multiple times.
other._data = nullptr;
other._length = 0;
}
当标记为赋值1和赋值2的指令覆盖_data和_length的值时,_data(nullptr),_ length(0)的用途是什么？
解决方法
当然应该是
// Move constructor.
MemoryBlock(MemoryBlock&& other) : _data(other._data),_length(other._length)
{
std::cout << "In MemoryBlock(MemoryBlock&&). length = "
<< other._length << ". Moving resource." << std::endl;
// Release the data pointer from the source object so that
// the destructor does not free the memory multiple times.
other._data = nullptr;
other._length = 0;
}
