Problems: (Page 372) There are two problems with the use of proprocessor macros in C++. The first is also with C: a macro looks like a function call, but does not act like one. This can bury difficult-to-find bugs. The second problem is specific to C…

［why inline functions must be put in header files?］ 编译中有2个过程:compile.link.先进行compile,compile中把源代码编译成目标代码(.obj),然后是link,把目标代码(obj)中的外部符号替换为真实的地址. inline函数的作用是减少函数调用而直接使用函数内部内容,显示是发生在compile阶段.所以如果把inline函数放在cc文件中,则compile过程中无法实现inline效果,连接器将给出 “unreso…

4.5 Inline Functions 以下是Point class 的一个加法运算符的可能实现内容: class Point { friend Point operator+(const Point&, const Point&); }; Point operator+(const Point &lhs, const Point &rhs) { Point new_pt; new_pt._x = lhs._x + rhs._x; new_pt._y = lhs._y +…

影响性能的一个重要因素是内联技巧.内联函数也可称为内嵌函数. 在C++中,函数调用需要建立栈环境,进行参数复制,保护调用现场,返回时,还要进行返回值复制,恢复调用现场.这些工作都是与完成特定任务的操作无关的额外开销.程序效率由于该项工作而受到影响. 可以将函数声明为内联函数.对函数的内联声明必须在调用之前.因为内联函数的代码在程序运行时是直接嵌在调用执行处,它不影响链接,只在编译时确定运行代码.因此编译时,在调用之前看到内联函数声明就十分重要. 内联函数体应该尽可能小,且结构要简单,不能含有复杂…

https://stackoverflow.com/questions/30045871/sorting-the-view-based-on-frequency-in-sql-server Just like in sub queries, you can't use ORDER BY in a view definition in sql server unless you also use TOP. The reason for this is that Views are acted up…

关于inline这个关键字,听到强调得最多的是,它只是一种对于编译器的建议,而非强制执行的限定. 但事实上,即使这个优化最终由于函数太过复杂的原因没有达成,加上inline关键字(还有在类定义中直接定义的函数也相当于加上了inline关键字)还是会带来一些区别的. 参看C++11标准文档里面的描述: A function declaration (8.3.5, 9.3, 11.3) with an inline specifier declares an inline function. The…

原文链接:http://www.drdobbs.com/cpp/standard-c-programming-virtual-functions/184403747 By Josée Lajoie and Stanley Lippman, September 01, 2000 As we gain mastery of C++, it is natural to question the rules of thumb that helped us get by in the beginning.…

Functions Functions allow to structure programs in segments of code to perform individual tasks. In C++, a function is a group of statements that is given a name, and which can be called from some point of the program. The most common syntax to defin…

About why inline member function should defined in the header file. It is legal to specify inline on both the declaration and the definition. But the keyword inline must be placed with the function definition body to make the function inline. Just pu…

In C, we have used Macro function an optimized technique used by compiler to reduce the execution time etc. So Question comes in mind that what’s there in C++ for that and in what all better ways? Inline function is introduced which is an optimizatio…