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When is a C++ destructor called?
...rwise, means it uses ::operator new). Then, when you use (for example) push_back to add an item to the vector, internally the vector uses a placement new to create an item in the (previously) unused part of its memory space.
Now, what happens when/if you erase an item from the vector? It can't just ...
Read a text file using Node.js?
...var path = require('path');
var readStream = fs.createReadStream(path.join(__dirname, '../rooms') + '/rooms.txt', 'utf8');
let data = ''
readStream.on('data', function(chunk) {
data += chunk;
}).on('end', function() {
console.log(data);
});
...
byte[] to hex string [duplicate]
...bove 2 but requires an array of 256 strings to always exist
With: LONG_STRING_LENGTH = 1000 * 1024;
BitConvertRep calculation Time Elapsed 27,202 ms (fastest built in/simple)
StringBuilder calculation Time Elapsed 75,723 ms (StringBuilder no reallocate)
LinqConcat calculation Time E...
Python naming conventions for modules
...and so I'd always have to name my instances something unnatural like client_instance. What do you think of this problem?
– Ray
Jun 1 '16 at 10:59
3
...
Returning a C string from a function
... you move over to C++ you'll use similar strategies:
class Foo
{
char _someData[12];
public:
const char* someFunction() const
{ // The final 'const' is to let the compiler know that nothing is changed in the class when this function is called.
return _someData;
}
}
... but...
Detect if the app was launched/opened from a push notification
...pplication wake up most recently?
func applicationWillEnterForeground(_ application: UIApplication) {
// time stamp the entering of foreground so we can tell how we got here
wakeTime = Date()
}
func application(_ application: UIApplication, didReceiveRemoteNotification userIn...
Why is creating a Thread said to be expensive?
...of OpenJDK 6 on Linux, the thread stack is allocated by the call to pthread_create that creates the native thread. (The JVM does not pass pthread_create a preallocated stack.)
Then, within pthread_create the stack is allocated by a call to mmap as follows:
mmap(0, attr.__stacksize,
PROT_REA...
What does .SD stand for in data.table in R
... may help you see what .SD is:
DT[ , .SD[ , paste(x, v, sep="", collapse="_")], by=y]
# y V1
# 1: 1 a1_b3_c5
# 2: 3 a2_b4_c6
Basically, the by=y statement breaks the original data.table into these two sub-data.tables
DT[ , print(.SD), by=y]
# <1st sub-data.table, called '.SD' while i...
Cannot use ref or out parameter in lambda expressions
... if (tokenDefinition.LeftDenotation != null)
token._led = tokenDefinition.LeftDenotation(token);
if (tokenDefinition.NullDenotation != null)
token._nud = tokenDefinition.NullDenotation(token);
token.Identifier = tokenDefinition.Identifi...
Symbolicating iPhone App Crash Reports
...above (using cd command)
Run atos -arch armv7 -o APPNAME.app/APPNAME MEMORY_LOCATION_OF_CRASH. The memory location should be the one at which the app crashed as per the report.
Ex: atos -arch armv7 -o 'APPNAME.app'/'APPNAME' 0x0003b508
This would show you the exact line, method name which resul...