通过汇编分下值类型的本质. 一.值类型 值类型赋值给var,let或者给参数传参,是直接将所有内容拷贝一份.类似于对文件进行复制粘贴操作,产生了全新的文件副本,属于深拷贝(deep copy). 示例: func testStruct() { struct Point { var x: Int var y: Int } var p1 = Point(x: 10, y: 20) print("before:p1.x:\(p1.x),p1.y:\(p1.y)") var p2 = p1 p
1. 要编译的测试代码: int a; int b = 3; int main(void) { if (3) a = 4; else b = 5; } 2. 词法分析 词法分析将c源代码解析成一个个的token. 关键的,将if两个字符解析成一个if token,后续语法分析的输入就从两个字符减少为1个token,减小了语法分析的难度. 3. 语法分析 if (equal(tok, "if")) { Node *node = new_node(ND_IF, tok); tok = sk
macname@ubuntu:~/Desktop$ roslaunch blackrospack: error : cannot open shared object file: No such file or directory Traceback (most recent call last): File , in <module> import roslaunch File , in <module> import rospkg ImportError: No module
macname@ubuntu:/opt$ roslaunch blarospack : error : cannot open shared object file: No such file or directory Traceback (most recent call last): File , in <module> import roslaunch File , in <module> import rospkg ImportError: No module named
