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What is the difference between std::array and std::vector? When do you use one over other? [duplicat
...ssic C array. That means its size is fixed at compile time and it will be allocated as a single chunk (e.g. taking space on the stack). The advantage it has is slightly better performance because there is no indirection between the object and the arrayed data.
std::vector is a small class contain...
Why are hexadecimal numbers prefixed with 0x?
...his is great because
an integer constant now always consists of a single token,
the parser can still tell right away it's got a constant,
the parser can immediately tell the base (0 is the same in both bases),
it's mathematically sane (00005 == 05), and
no precious special characters are needed (a...
Creating an array of objects in Java
...is:
A a1;
A a2;
A a3;
A a4;
Now you couldn't do a1.someMethod() without allocating a1 like this:
a1 = new A();
Similarly, with the array you need to do this:
a[0] = new A();
...before using it.
share
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How to generate a random string of a fixed length in Go?
...n terms of speed, and it will definitely help in terms of memory usage and allocations.
func RandStringBytesMaskImprSrcSB(n int) string {
sb := strings.Builder{}
sb.Grow(n)
// A src.Int63() generates 63 random bits, enough for letterIdxMax characters!
for i, cache, remain := n-1, sr...
How to embed small icon in UILabel
...tKit. Some sample code:
NSTextAttachment *attachment = [[NSTextAttachment alloc] init];
attachment.image = [UIImage imageNamed:@"MyIcon.png"];
NSAttributedString *attachmentString = [NSAttributedString attributedStringWithAttachment:attachment];
NSMutableAttributedString *myString= [[NSMutableAtt...
converting Java bitmap to byte array
...
This approach is really wastefull of allocations. Your ByteArrayOutputStream will allocate a byte[] of size equal to the byte[] backing your Bitmap, then ByteArrayOutputStream.toByteArray() will again allocate yet another byte[] of the same size.
...
Dismiss keyboard by touching background of UITableView
...hod:
UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(hideKeyboard)];
[self.tableView addGestureRecognizer:gestureRecognizer];
And the hideKeyboard method might look like this:
- (void) hideKeyboard {
[textField1 resignFirstResp...
Differences between C++ string == and compare()?
...or==
21.4.8.2 operator==
template<class charT, class traits, class Allocator>
bool operator==(const basic_string<charT,traits,Allocator>& lhs,
const basic_string<charT,traits,Allocator>& rhs) noexcept;
Returns: lhs.compare(rhs) == 0.
Seems like ...
How is std::function implemented?
... dynamically. The std::function object is always of the same size and will allocate space as needed for the different functors in the heap.
In real life there are different optimizations that provide performance advantages but would complicate the answer. The type could use small object optimizatio...
Setting Environment Variables for Node to retrieve
...SLATION_API_URL=/translations/
GA_UA=987654321-0
NEW_RELIC_KEY=hi-mom
SOME_TOKEN=asdfasdfasdf
SOME_OTHER_TOKEN=zxcvzxcvzxcv
You should not include the .env in your version control repository (add it to your .gitignore file).
To get variables from the .env file into your environment, you can use a...