聊聊C++中右值引用和移动构造函数的使用

int main()
{
	int i = 10;
	int j = 11;

	int sum = i + j;
}

int main()
{
	int i = 10;
	int& k = i;		//左值引用


	int&& m = 10;	//右值引用
}

    33: 	int i = 10;
00FB182F  mov         dWord ptr [ebp-0Ch],0Ah  
    34: 	int& k = i;	
00FB182F  mov         dword ptr [ebp-0Ch],0Ah  
00FB1836  lea         eax,[ebp-0Ch]  
00FB1839  mov         dword ptr [ebp-18h],eax  
    36: 	int&& m = 10;	
00FB183C  mov         dword ptr [ebp-30h],0Ah  
00FB1843  lea         eax,[ebp-30h]  
00FB1846  mov         dword ptr [ebp-24h],eax 

#include <iOStream>
#include <vector>

using namespace std;

class StringBuidler {
public:
	char* str;
	int length;
public:
	StringBuidler() {}
	StringBuidler(int len, char c) {
		this->str = new char[len];
		this->str[0] = c;
		this->length = len;
	}

	StringBuidler(const StringBuidler& s) {

		printf("StringBuidler：深复制 \n");
		this->length = s.length;
		this->str = new char[s.length];

		for (size_t i = 0; i < length; i++)
		{
			this->str[i] = s.str[i];
		}
	}

	StringBuidler operator+(const StringBuidler& p) {

		StringBuidler tmp;

		tmp.length = this->length + p.length;
		tmp.str = new char[tmp.length];

		int index = 0;

		for (size_t i = 0; i < this->length; i++)
		{
			tmp.str[index++] = this->str[i];
		}
		for (size_t i = 0; i < p.length; i++)
		{
			tmp.str[index++] = p.str[i];
		}

		return tmp;
	}
};

int main()
{
	StringBuidler s1(10, 'a');
	StringBuidler s2(5, 'b');

	StringBuidler s3 = s1 + s2;

	printf("s3.length=%d, s1.length=%d, s2.length=%d \n", s3.length, s1.length, s2.length);
}

	StringBuidler(StringBuidler&& s) {
		this->str = s.str;
		this->length = s.length;

		s.str = nullptr;
	}