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Is it safe to get values from a java.util.HashMap from multiple threads (no modification)?
...ting thread makes the reference to the map visible to other threads.
Basically, the only possible race here is between the construction of the HashMap and any reading threads that may access it before it is fully constructed. Most of the discussion is about what happens to the state of the map obje...
Can we have functions inside functions in C++?
...rm of a lambda:
int main() {
// This declares a lambda, which can be called just like a function
auto print_message = [](std::string message)
{
std::cout << message << "\n";
};
// Prints "Hello!" 10 times
for(int i = 0; i < 10; i++) {
print...
Performance difference for control structures 'for' and 'foreach' in C#
...t will depend on whether you're doing any real work in the loop. In almost all cases, the difference to performance won't be significant, but the difference to readability favours the foreach loop.
I'd personally use LINQ to avoid the "if" too:
foreach (var item in list.Where(condition))
{
}
EDI...
What makes a keychain item unique (in iOS)?
...the keychain access group (field kSecAttrAccessGroup) is an added field to all these primary keys.
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examining history of deleted file
...
When you want to look at old files you really should know the difference between:
svn cat http://server/svn/project/file -r 1234
and
svn cat http://server/svn/project/file@1234
The first version looks at the path that is now available as http://server/svn/proj...
Can you animate a height change on a UITableViewCell when selected?
...
I found a REALLY SIMPLE solution to this as a side-effect to a UITableView I was working on.....
Store the cell height in a variable that reports the original height normally via the tableView: heightForRowAtIndexPath:, then when you wa...
Does Foreign Key improve query performance?
...n FK does not create an associated index, and you should create indexes on all FK fields to improve look up times.
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When do I need to use Begin / End Blocks and the Go keyword in SQL Server?
... a way of isolating one part of the script from another, but submitting it all in one block.
BEGIN and END are just like { and } in C/++/#, Java, etc.
They bound a logical block of code. I tend to use BEGIN and END at the start and end of a stored procedure, but it's not strictly necessary ther...
Perform debounce in React.js
...>
AwesomeDebouncePromise(searchFunction, 300)
);
// The async callback is run each time the text changes,
// but as the search function is debounced, it does not
// fire a new request on each keystroke
const searchResults = useAsync(
async () => {
if (inputText.length ...
Comparing two dictionaries and checking how many (key, value) pairs are equal
... will fail on values that aren't hashable.
– Tim Tisdall
Apr 10 '17 at 13:51
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