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Is Using .NET 4.0 Tuples in my C# Code a Poor Design Decision?
...pport for tuples in C#:
private var GetDesserts()
{
return _icecreams.Select(
i => new { icecream = i, topping = new Topping(i) }
);
}
public void Eat()
{
foreach (var dessert in GetDesserts())
{
dessert.icecream.AddTopping(dessert.topping);
dessert.Eat()...
How are multi-dimensional arrays formatted in memory?
...
unsigned char MultiArray[5][2]={{0,1},{2,3},{4,5},{6,7},{8,9}};
in memory is equal to:
unsigned char SingleArray[10]={0,1,2,3,4,5,6,7,8,9};
share
...
Hidden features of C
...
Multi-character constants:
int x = 'ABCD';
This sets x to 0x41424344 (or 0x44434241, depending on architecture).
EDIT: This technique is not portable, especially if you serialize the int.
However, it can be extremely useful to ...
C++ new int[0] — will it allocate memory?
...t be reasonable to say that a computer executing a while(!exitRequested) { char *p = new char[0]; delete [] p; } loop without recycling pointers would collapse into dust before it could possibly run out of address space, but on a platform with 32-bit pointers that would be a far less reasonable assu...
Difference between >>> and >>
...as really refering to (imho), is that a String could also be regarded as a char[]. He's not saying that a char is not a number ; he's just saying that it's an unsigned number. I think that's where he's lost.
– bvdb
Aug 17 '15 at 10:33
...
What is a good Hash Function?
... that differ only in the last 4 bytes can collide easily. If you have a 30 character string, that differ in the last 4 bytes, after 28 bytes have been processes, the hashes differ only in the last 2 bytes. That means you are GUARANTEED a collision for one of the remaining two-byte values. (Yeah, it'...
Why is it impossible to build a compiler that can determine if a C++ function will change the value
... /* modify variable */
variable = 1;
}
}
int main(int argc, char **argv) {
if (modifies_variable(f, variable)) {
printf("Modifies variable\n");
} else {
printf("Does not modify variable\n");
}
return 0;
}
...
Implement touch using Python?
...'atime', c_timespec), ('mtime', c_timespec)]
utimens = CFUNCTYPE(c_int, c_char_p, POINTER(c_utimbuf))
futimens = CFUNCTYPE(c_int, c_char_p, POINTER(c_utimbuf))
# from /usr/include/i386-linux-gnu/bits/stat.h
UTIME_NOW = ((1l << 30) - 1l)
UTIME_OMIT = ((1l << 30) - 2l)
now = c_timespe...
STL中map容器使用自定义key类型报错详解 - C/C++ - 清泛网 - 专注C/C++及内核技术
...写测试代码定义一个结构体来试试:[cpp]view plaincopystructa{char*pName;intm_a;} 引言
STL的map容器中,key的类型是不是随意的呢?
实践
编写测试代码
定义一个结构体来试试:
struct a
{
char* pName;
int m_a;
};
...
map<a, i...
Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?
...n multiple courses, books, and jobs, I have seen text fields defined as VARCHAR(255) as kind of the default for "shortish" text. Is there any good reason that a length of 255 is chosen so often, other than being a nice round number ? Is it a holdout from some time in the past when there was a goo...
