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Why don't structs support inheritance?
...hat short[] can't be converted to int[] (short of conversion code, like 'a.Select(x => (int) x).ToArray()'). If the runtime disallowed the cast from Base to Derived, it would be a "wart", as that IS allowed for reference types. So we have two different "warts" possible -- forbid struct inherita...
How to determine if a number is a prime with regex?
...nerated has a length equal to the number supplied. So the string has three characters if and only if n == 3.
.?
The first part of the regex says, "any character, zero or one times". So basically, is there zero or one character-- or, per what I mentioned above, n == 0 || n == 1. If we have the mat...
Is it better to use std::memcpy() or std::copy() in terms to performance?
...in as large of chunks as possible (many other implementations operate with char / char *, whereas I operate with T / T * (where T is the largest type in the user's implementation that has correct overflow behavior), so fast memory access on the largest types I can is central to the performance of my...
What is the difference between Ruby 1.8 and Ruby 1.9
...ow
if statements do not introduce scope in Ruby.
What's changed?
Single character strings.
Ruby 1.9
irb(main):001:0> ?c
=> "c"
Ruby 1.8.6
irb(main):001:0> ?c
=> 99
String index.
Ruby 1.9
irb(main):001:0> "cat"[1]
=> "a"
Ruby 1.8.6
irb(main):001:0> "cat"[1]
=>...
Check if a string contains a number
...n, like this
>>> def hasNumbers(inputString):
... return any(char.isdigit() for char in inputString)
...
>>> hasNumbers("I own 1 dog")
True
>>> hasNumbers("I own no dog")
False
Alternatively you can use a Regular Expression, like this
>>> import re
>&g...
How to find out line-endings in a text file?
...
Unfortunately, I don't think vi can show those specific characters. You can try od -c <filename> which I believe will display \n or \r\n.
– Ryan Berger
Aug 25 '10 at 22:51
...
C++静态和多态，亦敌亦友 - C/C++ - 清泛网 - 专注C/C++及内核技术
...(void){ cout << "DerivedAgain::foo()"<< endl; }
} ;
int main(int argc, char** argv)
{
DerivedAgain da;
Base* pB = &da;
da.foo();
pB->foo();
return 0;
}
上述代码运行结果是什么？等等，你确定上述代码能通过编译？在笔者Ubuntu 12.04 + gcc...
Can I mask an input text in a bat file?
...d. Do I have any way to mask the input text? I don't need to print ******* characters instead of input characters. Linux's Password prompt behavior (Print nothing while typing) is enough.
...
Avoiding if statement inside a for loop?
... f(index++, e);
}
int main() {
using namespace std;
set<char> s{'b', 'a', 'c'};
// indices starting at 1 instead of 0
for_each_indexed(s, [](size_t i, char e) { cout<<i<<'\t'<<e<<'\n'; }, 1u);
cout << "-----" << endl;
vecto...
How to insert a character in a string at a certain position?
...
This solution works for any string >= 4 characters: the string "111" gave me ".111", and anything less than that results in a java.lang.StringIndexOutOfBoundsException (attempting to access a reference that doesn't exist).
– sotrh
...