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Why is it string.join(list) instead of list.join(string)?
...ned (e.g, list, tuple, dict, set), but the result and the "joiner" must be strings.
For example:
'_'.join(['welcome', 'to', 'stack', 'overflow'])
'_'.join(('welcome', 'to', 'stack', 'overflow'))
'welcome_to_stack_overflow'
Using something else than strings will raise the following error:
T...
boost自定义composite_key_compare比较函数 - C/C++ - 清泛网 - 专注C/C++及内核技术
...DType,&TParam::ID>
>,
composite_key_compare<
//std::less<std::string>
customize_compare
>
>,
ordered_non_unique< tag<TParamValidIndex>,
member<TParam,bool,&TParam::IsValid> >
>
>TParamSet;
typedef boost::multi_index::index<TParamSet,TParamIDIndex>::type TParamSetBy...
Why do people say there is modulo bias when using a random number generator?
... particularly hard to avoid in computing, where numbers are represented as strings of bits: 0s and 1s. Finding truly random sources of randomness is also extremely difficult, but is beyond the scope of this discussion. For the remainder of this answer, assume that there exists an unlimited source of...
How to persist a property of type List in JPA?
... should anyone be looking for an alternative solution where you store your string lists as one field in your database, here's how I solved that. Create a Converter like this:
import java.util.Arrays;
import java.util.List;
import javax.persistence.AttributeConverter;
import javax.persistence.Conve...
Is there an auto increment in sqlite?
...ect (bold & italic are mine):
The AUTOINCREMENT keyword imposes extra CPU, memory, disk space, and
disk I/O overhead and should be avoided if not strictly needed. It is
usually not needed.
In SQLite, a column with type INTEGER PRIMARY KEY is an alias for the
ROWID (except in WITHO...
What is the purpose of using -pedantic in GCC/G++ compiler?
...f more extensions and generates more warnings. For example, if you have a string literal longer than 509 characters, then -pedantic warns about that because it exceeds the minimum limit required by the C89 standard. That is, every C89 compiler must accept strings of length 509; they are permitted ...
Easiest way to detect Internet connection on iOS?
...all native C code snippet that can check internet connectivity without any extra class.
Add the following headers:
#include<unistd.h>
#include<netdb.h>
Code:
-(BOOL)isNetworkAvailable
{
char *hostname;
struct hostent *hostinfo;
hostname = "google.com";
hostinfo = get...
RegEx to find two or more consecutive chars
I need to determine if a string contains two or more consecutive alpha chars. Two or more [a-zA-Z] side by side.
Example:
...
What is a segmentation fault?
...as marked as read-only:
char *str = "Foo"; // Compiler marks the constant string as read-only
*str = 'b'; // Which means this is illegal and results in a segfault
Dangling pointer points to a thing that does not exist any more, like here:
char *p = NULL;
{
char c;
p = &c;
}
// Now p ...
How to replace a hash key with another key
...
If all the keys are strings and all of them have the underscore prefix, then you can patch up the hash in place with this:
h.keys.each { |k| h[k[1, k.length - 1]] = h[k]; h.delete(k) }
The k[1, k.length - 1] bit grabs all of k except the firs...