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What is “rvalue reference for *this”?
... of the "implicit object parameter" of the function†:
// t.cpp
#include <iostream>
struct test{
void f() &{ std::cout << "lvalue object\n"; }
void f() &&{ std::cout << "rvalue object\n"; }
};
int main(){
test t;
t.f(); // lvalue
test().f(); // rvalue
}
Ou...
How to delete a row by reference in data.table?
...
@rbatt Correct. DT[b<8 & a>3] returns a new data.table. We'd like to add delete(DT, b>=8 | a<=3) and DT[b>=8 | a<=8, .ROW:=NULL]. The advantage of the latter would be combining with other features of [] such as row numbers i...
Meaning of @classmethod and @staticmethod for beginner? [duplicate]
...day, month, year = map(int, date_as_string.split('-'))
return day <= 31 and month <= 12 and year <= 3999
date2 = Date.from_string('11-09-2012')
is_date = Date.is_date_valid('11-09-2012')
Explanation
Let's assume an example of a class, dealing with date information (this will be ...
Cast Object to Generic Type for returning
...ce because of the generic type erasure during compilation.
public static <T> T convertInstanceOfObject(Object o, Class<T> clazz) {
try {
return clazz.cast(o);
} catch(ClassCastException e) {
return null;
}
}
The declaration of that method is:
public T cast...
How to match all occurrences of a regex
...ethod, use:
str.to_enum(:scan, /\d+/).map { Regexp.last_match }
#=> [#<MatchData "54">, #<MatchData "3">, #<MatchData "1">, #<MatchData "7">, #<MatchData "3">, #<MatchData "36">, #<MatchData "0">]
The benefit of using MatchData is that you can use meth...
Advantage of creating a generic repository vs. specific repository for each object?
...xample, using LINQ to SQL, you could do:
public abstract class Repository<TEntity>
{
private DataContext _dataContext;
protected Repository(DataContext dataContext)
{
_dataContext = dataContext;
}
protected IQueryable<TEntity> Query
{
get { retu...
Searching if value exists in a list of objects using Linq
...e a class Customer which has a property FirstName . Then I have a List<Customer> .
9 Answers
...
Android and setting alpha for (image) view alpha
...tes" section is missing in the ImageView.setAlpha(int) documentation. The alternative is to use View.setAlpha(float) whose XML counterpart is android:alpha. It takes a range of 0.0 to 1.0 instead of 0 to 255. Use it e.g. like
<ImageView android:alpha="0.4">
However, the latter in available ...
How to create a new branch from a tag?
...
If this doesn't work because of "<tag> is not a valid commit" or a similar error (often when working on a shared repository), refer to stackoverflow.com/questions/35979642/…
– SalmonKiller
Nov 9 '18 at 23:04
...
Saving and loading objects and using pickle
...
As for your second problem:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python31\lib\pickle.py", line
1365, in load encoding=encoding,
errors=errors).load() EOFError
After you have read the contents of the file, the file pointer will be at th...