大约有 30,000 项符合查询结果（耗时：0.0487秒） [XML]
C++ - passing references to std::shared_ptr or boost::shared_ptr
...a message somewhere. It may be a large message so rather than using a std::string that likely gets copied as it is passed around to multiple places, we use a shared_ptr to a string:
void send_message(std::shared_ptr<std::string> msg)
{
std::cout << (*msg.get()) << std::endl;
}...
Are HLists nothing more than a convoluted way of writing tuples?
...(t2)
val t2b = f2.tupled
// Inferred type of t2b is (Int, Boolean, Double, String, String, Int, Boolean)
Without using HLists (or something equivalent) to abstract over the arity of the tuple arguments to flatten it would be impossible to have a single implementation which could accept arguments o...
byte[] to file in Java
...e(filePath).toPath(), data);
Where data is your byte[] and filePath is a String. You can also add multiple file open options with the StandardOpenOptions class. Add throws or surround with try/catch.
share
|
...
What is the relative performance difference of if/else versus switch statement in Java?
... First create some interface:
public interface Action {
void execute(String input);
}
And get hold of all implementations in some Map. You can do this either statically or dynamically:
Map<String, Action> actions = new HashMap<String, Action>();
Finally replace the if/else or ...
JPG vs. JPEG image formats
...ut it is inaccurate. • The JPEG group were mostly Unix shops, thus the 4-char .jpeg extension, not because of Mac. • It was the DOS 8.3 limit that caused the shortening to .jpg — windows was just a shell on top of DOS. • The commonly accepted .jpg form is because of programs that had to cope...
Using scanner.nextLine() [duplicate]
...mber, not the end of line or anything after the number. When you declare
String sentence = scanner.nextLine();
This reads the remainder of the line with the number on it (with nothing after the number I suspect)
Try placing a scanner.nextLine(); after each nextInt() if you intend to ignore the...
SQL - The conversion of a varchar data type to a datetime data type resulted in an out-of-range valu
...
Just used cast(SUBSTRING([MyDateField],1,2) as integer) > 31 and found a record with the 60th of December. Who enters this stuff, Dr Suess?
– SteveCav
Oct 21 '15 at 22:11
...
sqlite alter table add MULTIPLE columns in a single statement
...und for adding multiple columns using the benefit of transactions in SQL.
String alterTableQuery = "ALTER TABLE " + TABLE_NAME + " ADD COLUMN ";
List<String> newColumns = ..// Your new columns
db.beginTransaction();
for (String column : newColumns){
db.execSQL(alterTableQuery + column + ...
What is output buffering?
...n pieces as PHP processes the HTML.
All the fancy stuff we can do with PHP strings, we can now do with our whole HTML page as one variable.
If you've ever encountered the message "Warning: Cannot modify header information - headers already sent by (output)" while setting cookies, you'll be happy to ...
Bootstrap close responsive menu “on click”
...
You don't have to add any extra javascript to what's already included with bootstraps collapse option. Instead simply include data-toggle and data-target selectors on your menu list items just as you do with your navbar-toggle button. So for your Pr...