大约有 36,000 项符合查询结果（耗时：0.0177秒） [XML]
Why is address zero used for the null pointer?
...
@GMan - You are correct. On early CPUs, memory address zero was special and had hardware protection against access from running software (in some cases it was the start of the reset vector, and modifying it could prevent the CPU from resetting or starting up)...
Subversion钩子 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...一个PHP项目使用Subversion做版本控制，使用中发现了一些问题，比如程序员不写日志，或者提交的文件有BOM，或者提交的文件有语法错误，或者提交的文件不符合编码规范等等，这些问题都可以利用pre-commit钩子来解决，实际上已...
Discuz X 首页白板解决之道 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...在合适位置打印特定内容然后exit(0);查看结果，分析出现问题的 1、开启Debug，及url后面跟 &debug=yes，也是网上最多的方法，但可能往往没有效果。
2、排除法，代码一段段的排查，在合适位置打印特定内容然后exit(0);查看结果，...
提问 - App Inventor 2 中文网 - 清泛IT社区，为创新赋能！
...sp;使用下面程序时，为什么每次都会把实际数字设为0？
问题出在你的判断逻辑上：
这里和你拼接的字符串比较，非常容易出错，比如多了或少了一个空格等。实际编程中判断最好使用数字，也就是你选择了难度等级是第几...
最大装载数不显示计算数值 - App Inventor 2 中文网 - 清泛IT社区，为创新赋能！
...数输出+（高数输出×横数输出）÷2＝最大装载数
出现问题不显示计算数字代码块没有问题，经过测试是能够正确计算出除法结果的，测试时主要被除数要大于除数，否则计算结果0.xxx 向下取整就是0，干扰测试结果。。。之后...
Why does my application spend 24% of its life doing a null check?
...uting instructions, it is accessing memory. The execution core of a modern CPU is many times faster than the memory bus. A problem related to distance, the further an electrical signal has to travel, the harder it gets to get that signal delivered to the other end of the wire without it being corrup...
Stack Memory vs Heap Memory [duplicate]
...m C++.
Generally speaking, the stack is preferred as it is usually in the CPU cache, so operations involving objects stored on it tend to be faster. However the stack is a limited resource, and shouldn't be used for anything large. Running out of stack memory is called a Stack buffer overflow. It's...
Virtual functions and performance - C++
...curious, so I went ahead and ran some timings on the 3GHz in-order PowerPC CPU we work with. The test I ran was to make a simple 4d vector class with get/set functions
class TestVec
{
float x,y,z,w;
public:
float GetX() { return x; }
float SetX(float to) { return x=to; } // and so on...
How can I check if a Perl array contains a particular value?
...grep, hash...
any: 0 wallclock secs ( 0.67 usr + 0.00 sys = 0.67 CPU) @ 149253.73/s (n=100000)
first: 1 wallclock secs ( 0.63 usr + 0.01 sys = 0.64 CPU) @ 156250.00/s (n=100000)
grep: 42 wallclock secs (41.95 usr + 0.08 sys = 42.03 CPU) @ 2379.25/s (n=100000)
hash: 0 ...
Debug Error \"pure virtual function call\" 原因解析 - 更多技术 - 清泛...
...函数中抛出异常，不然，我们不得不面对以下两个严重的问题：
二次异常导致程序退出;
遗留下来的未完全销毁的对象与未完成的工作导致的后续问题
pure virtual function call就是这种情况。
但是理想与现实总是有差距的，...