大约有 41,000 项符合查询结果(耗时:0.0583秒) [XML]
What is the difference between char s[] and char *s?
...
static char __unnamed[] = "abc";
char *c = __unnamed;
Note the implicit cast from char[] to char *, which is always legal.
Then if you modify c[0], you also modify __unnamed, which is UB.
This is documented at 6.4.5 "String literals":
5 In translation phase 7, a byte or code of value zero i...
When should I use mmap for file access?
...he buffers are often properly aligned and do not trap when dereferencing a casted pointer.
You also have to be careful that you do not access outside of the map. It can easily happen if you use string functions on your map, and your file does not contain a \0 at the end. It will work most of the ti...
What is the purpose of AsQueryable()?
... change the compile time type of the object to IQueryable. You could just cast it, but by having an AsQueryable method you can take advantage of type inference. This is simply more convenient if the generic argument list is complex, and it is actually necessary if any of the generic arguments are ...
How does Bluebird's util.toFastProperties function make an object's properties “fast”?
...;IsJSObject()) {
JSObject::OptimizeAsPrototype(Handle<JSObject>::cast(value));
}
Which in turn is called by FuntionSetPrototype which is what we get with .prototype =.
Doing __proto__ = or .setPrototypeOf would have also worked but these are ES6 functions and Bluebird runs on all browsers...
What's the difference between size_t and int in C++?
...G_PTR is an unsigned long type used for pointer precision. It is used when casting a pointer to a long type to perform pointer arithmetic.
This type is declared as follows:
typedef unsigned __int3264 ULONG_PTR;
share
...
C++对象布局及多态探索之菱形结构虚继承 - C/C++ - 清泛网 - 专注C/C++及内核技术
...们做个指针的动态转型再调用一次:
C141 * pt1 = dynamic_cast (pt);
pt1-> foo();
第1行代码对应的汇编指令如下:
01 00423FBD cmp dword ptr [ebp+FFFFF73Ch],0
02 00423FC4 je 00423FD7
03 00423FC6 mov eax,dword ptr [ebp+FFFFF73Ch]
04 00423FCC add eax,5
0...
Why are C# 4 optional parameters defined on interface not enforced on implementing class?
...act of that is the behavior you see where you get different results if you cast to an interface.
share
|
improve this answer
|
follow
|
...
Position of least significant bit that is set
...her bytes by storing/reloading instead of shifting, because of the pointer-cast. (totally unnecessary BTW, and makes it endian-dependent unlike a shift wouldn't). Anyway, so not only is the microbenchmark unrealistic because of hot cache, it also has the branch predictors primed and tests inputs t...
Is the “struct hack” technically undefined behavior?
...instead of explicitly adding the offset to the pointer returned by malloc, cast to char *, is irrelevant.
Technically, p->s[0] is the single element of the char array inside the struct, the next few elements (e.g. p->s[1] through p->s[3]) are likely padding bytes inside the struct, which c...
What is Rack middleware?
...mment about it being a way to filter requests probably comes from the RailsCast episode 151: Rack Middleware screen cast.
Rack middleware evolved out of Rack and there is a great intro at Introduction to Rack middleware.
There's an intro to middleware on Wikipedia here.
...