if defined

We're going to check if a is defined.#if defined A#undef A#define a 200#endifThe above statement verifies whether a is defined and, if defined, is defined with the #undef statement and redefined a as 200#ifndef a //If A is not defined#define a

Tag:io    use    sp   on    file    div    bs    code    ad    First, let's start with the beginning of the file, in a lot of header files, we will see this statement #ifndef _myheadfile_h #define _MYHEADFILE_H//.... Statement ...

# If instructions # If followed by an expression # If (max = 10) | (max = 20) code... # endif Its function is: If (max = 10) | (max = 20) is true, then the compiler will compile the code between # If and # endif (Note: It is compiled, not

#if vs. if Conditional compilation is the content of the preprocessing section in C language, which is the first part of the compiler's compilation of code. Conditional compilation contains judgment statements, such as #if, #else, #elif, and #endif

Because for a largeProgramWe may need to define many constants (whether in the source file or header file), so when we sometimes consider defining a constant, we must return to check whether the original constant is defined, however, this is very

First, reference a section: _ Msc_ver Define the version of the compiler. The following are the _ msc_ver values of some compiler versions (see references 2 in extended reading) Ms vc ++ 9.0 _ msc_ver = 1500 Ms vc ++ 8.0 _ msc_ver = 1400

Preface 2017.01 Uboot contains two stages of start-up, one is SPL-initiated, and the other is a normal start-up we call the second stage of Uboot. Of course, we can also choose to use SPL and not to use it. In the process of compiling, the second

Use Perl to write a protocol analysis script Created on: updated on:Article attributes: originalArticle submission: r00t (I _am_jo_at_msn.com) 1. software environment: Windows, ActiveState Perl 5.8.6, Winpcap 3.1 beta;2. Perl modules: Net: pcap, net:

This is a creation in Article, where the information may have evolved or changed. This is a simple example of mine and is not perfect at the moment. Subsequent optimizations are required, such as the replacement of the thread lock, the addition of

0K6410 learning Uboot_stage2 Alas, my old classmates called me to get together at the end of the month. I swear that this was my first time so cool, that is, just as before, I agreed without consideration. Because, I think I have a lot of important

Copyright notice: This article by Hangyuan Li original article, reprint please indicate source:Article original link: https://www.qcloud.com/community/article/109Source: Tengyun https://www.qcloud.com/communityThe purpose of this article is to share

Program from start. s start start Start_code:/** Set the CPU to SVC32 mode settings management mode*/Mrs R0, CPSRBic R0, R0, #0x1fOrr R0, R0, #0xd3MSR CPSR, R0 #ifdef config_s3c24x0/* Turn off the watchdog */ /* off watchdog off interrupt */ # if

Copy Code code as follows: /* XML-RPC libraries found on the Web are useful for developing small external communication interfaces */ Function & Xml_serialize ($data, $level = 0, $prior _key = NULL) { #assumes a hash, keys are the

CPU: [Email protected]FCLK = 532MHz, hclk = 133MHz, Pclk = 66MHz, Serial = Clkuart (SYNC Mode)board:mini6410dram:256 MBflash:0 KBnand:2048 MBIn:serialOut:serialErr:serialMac:08:90:90:90:90:90The output information of the following code can be found

Phpxml-rpc remote call. Copy the code as follows :? Php * XML-RPC library found from the Internet, useful for developing small external communication interfaces * functionwhile (list ($ key, $ value) each ($ data) {$ inlinefa The code is as follows:

XML-RPC library from the Internet, for the development of small external communication interface is very useful, save this code as a xml-rpc.inc.php The code is as follows: /*XML-RPC library from the Internet, very useful for developing small

Copy CodeThe code is as follows: /* The XML-RPC library, which is found on the Internet, is useful for developing small external communication interfaces. */ Function & Xml_serialize ($data, $level = 0, $prior _key = NULL) { #assumes a hash, keys

C/C ++ macro usage Summary Macro replacement is the Technical Feature of the C/C ++ series languages. The C/C ++ language provides powerful macro replacement functions. Before the Source Code enters the compiler, first, a module called "Preprocessor"

Recently, I checked the content of the Space configurator and implemented the ACE_Allocator class of ACE, The allocator class implementation of SGI, And the allocator Implementation of MS. I also referred to Mr Hou Jie's STL source code analysis.

1, to determine whether the drive, file or folder exists, with if exist statement;2, to determine whether the two strings are equal, with the If "string 1" = "string 2" statement;3, to determine whether the two values are equal, using the IF value 1