const const

Item M17: Consider using lazy evaluation (lazy calculation method)From the point of view of efficiency, the best calculation is not the calculation at all, OK, but if you do not have to calculate at all, why do you still add code at the beginning of

When talking about MySQL subqueries and their optimization, DBAs or developers who have used oracle or other relational databases have such experience. in subqueries, they all think that the database has been optimized, it is good to choose to drive

Const legend Xlander Translation IntroductionWhen I write a program to use const, or read other people's code and encounter const, I often stop and think for a

Many excerpted contentTranslated by Aman JiangBox2d v2.0.1 User Manual Chapter 1 bodies) 7.1 about The position and speed of an object. You can apply the forces, torques, and impulses to an object. Objects can be static, moving but not forced

At noon on Saturday, I still came to the company and didn't intend to come. Now, let's solve some of the problems left over from the last time, let's sum up the pwm LCD Backlight for Android. The backlight of Android is controlled by PWM wave.

1. Consortium Union is a consortium. A consortium can contain one or more structs. The largest, small, and longest structs determine the length of a consortium and assign values to any member in the consortium, this causes other members to be reset

A summary of the const usage in C + + classes:Let's look at an example:Class A{PublicA (int x): num (x), b(x) {}　　void Fun (const a& A); const modifier Function Parameters　　int getnum (void) const; const modifier functions that do not modify member

MySQL's subquery optimization has been not very friendly, has been criticized by the industry more than I have encountered in the SQL optimization of one of the most problems, you can click here, here to get some information, MySQL processing

Reproduced from:Http://www.cnblogs.com/kkdd-2013/p/5370094.html C Set sail 1h 1 C Brief Introduction 2 Cide environment to build 3 C first experience 4 C language new features C new features C input and output cNAMESPACE 5 exercise C Departure 15h 1

An in-depth understanding of index merge is one of the important foundations for optimizing using indexes. Having understood the index merge technology, we know how to index the table.1. Why is there an index mergeThere may be multiple conditions

 C + + Primer 3rd reading notesCategory: C/c++/vc2014-04-08 20:43 318 people read Comments (0) favorite reports The first chapter begins1. Standard header files in C + + are not with the. h suffix. The following code is worth noting:

The use of the const keyword in C + + is very flexible, and using the const will greatly improve the robustness of the program, I found in various aspects of the information summarized below, hoping to help friends. Const is a type modifier commonly

"#define"#define是预处理指令, a simple substitution is made during the pre-processing of the compilation without checking for correctness."typedef"A typedef is simply a new name for the identifier to be added for readabilityGive an alias to an already

Introduction to a concept The index Condition pushdown (ICP) is a new feature in the MySQL 5.6 release and is an optimized way to use index filtering data at the storage engine level. A when the ICP is turned off, index is just one way of

Which definitions are the same for several statements? What are the different definitions? What data can be modified? What data is not modifiable?1 Const int A; 2 int Const A; 3 Const int *A; 4 INT *const A; 5 int Const *const A;In C + +, const is

In the program often encountered the const, but he did not know very well, today saw an article is very good, so copied over ....Original link: http://blog.csdn.net/Eric_Jo/article/details/4138548The use of the Const keyword in C + + is very

of the pointerConstThere are two kinds:ConstModifies the object that the pointer is pointing to, or modifies the address stored inside the pointer./*** book: "thinkinginc++" * Function: Const's delivery and return address * Time: September 7, 2014 14

The use of const in C + + is very extensive, different location to use the meaning is not the same, so want to write an article to make a summary. First of all, it is clear that the const is the basic meaning of "unchanging", but the same does not

Note: The const and typedef are very special when used together Trap One: Remember, a typedef is a new alias that defines a type, and unlike macro, it is not a simple string replacement. Like what:First define:typedef char* PSTR;And then:int

Index Condition pushdown (ICP) is an optimization method for MySQL to retrieve row data from a table using an index. Before the ICP attribute is found, the storage engine finds and returns data to the MySQL Server,mysql server based on the index to