I write a code section as this struct My{const int a;}; OK, then set the warning level then I will got this c:\users\luli1\documents\visual studio 2013\projects\consoleapplication3\header1.h(4): error C2220: warning treated as error - no 'object' fil…
Extraction from C++ primer 5th Edition 7.1.2 The purpose of the const that follows the parameter list of an ordinary member function is to modify the type of the implicit this pointer. By default, the type of this is a const pointer to the nonconst v…
//区别⑦:三目运算符(C++版本) #include<iostream> using namespace std; //三目运算符 C语言返回变量的值 C++语言是返回变量本身 void main(){ ; ; a < b ? a : b = ; //C++中的三目运算符可直接返回变量本身,因此可以出现在程序的任何地方 //注意: //三目运算符可能返回的值中如果有一个是常量值,则不能作为左值使用 //(a < b ? 1 : b) = 30; system("paus…
stat,lstat,fstat1 函数都是获取文件(普通文件,目录,管道,socket,字符,块()的属性.函数原型#include <sys/stat.h> int stat(const char *restrict pathname, struct stat *restrict buf);提供文件名字,获取文件对应属性. int fstat(int filedes, struct stat *buf);通过文件描述符获取文件对应的属性. int lstat(const char *res…
const类型变量--------------------------------------int i;const int *p; --------------------------------------int i;int *const p = &i;--------------------------------------int i;const int *const p = &i; 三者有何区别呢?-------------------------------------- 指向…
在我的文件里有这class NFDuration, NFDuration.h里是这样的: // A Duration represents the elapsed time between two instants // as an int64 nanosecond count. The representation limits the // largest representable duration to approximately 290 years. class NFDuration…
