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How can I add reflection to a C++ application?
...re are some handy macros to help with typed expressions:
#define REM(...) __VA_ARGS__
#define EAT(...)
// Retrieve the type
#define TYPEOF(x) DETAIL_TYPEOF(DETAIL_TYPEOF_PROBE x,)
#define DETAIL_TYPEOF(...) DETAIL_TYPEOF_HEAD(__VA_ARGS__)
#define DETAIL_TYPEOF_HEAD(x, ...) REM x
#define DETAIL_TYP...
Bash continuation lines
...here document. (Line terminators will still remain, though.)
cat <<-____HERE
continuation
lines
____HERE
See also http://ss64.com/bash/syntax-here.html
If you need to preserve some, but not all, leading whitespace, you might use something like
sed 's/^ //' <<____HERE
Th...
The tilde operator in Python
...s operator.invert. To support this operator in your own class, give it an __invert__(self) method.
>>> import operator
>>> class Foo:
... def __invert__(self):
... print 'invert'
...
>>> x = Foo()
>>> operator.invert(x)
invert
>>> ~x
invert
Any ...
What's wrong with using $_REQUEST[]?
I've seen a number of posts on here saying not to use the $_REQUEST variable. I usually don't, but sometimes it's convenient. What's wrong with it?
...
Getting the SQL from a Django QuerySet [duplicate]
...et = MyModel.objects.all()
>>> print(queryset.query)
SELECT "myapp_mymodel"."id", ... FROM "myapp_mymodel"
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How to convert a scala.List to a java.util.List?
...1,2,3))
From Scala 2.8 onwards:
import scala.collection.JavaConversions._
import scala.collection.mutable.ListBuffer
asList(ListBuffer(List(1,2,3): _*))
val x: java.util.List[Int] = ListBuffer(List(1,2,3): _*)
However, asList in that example is not necessary if the type expected is a Java List,...
Add CSS or JavaScript files to layout head from views or partial views
...Format);
}
}
public class ItemRegistrar
{
private readonly string _format;
private readonly IList<string> _items;
public ItemRegistrar(string format)
{
_format = format;
_items = new List<string>();
}
public ItemRegistrar Add(string url)
...
How do I perform the SQL Join equivalent in MongoDB?
...ttps://docs.mongodb.org/master/reference/operator/aggregation/lookup/#pipe._S_lookup
From the docs:
{
$lookup:
{
from: <collection to join>,
localField: <field from the input documents>,
foreignField: <field from the documents of the "from" collection>...
Select count(*) from multiple tables
...
Just because it's slightly different:
SELECT 'table_1' AS table_name, COUNT(*) FROM table_1
UNION
SELECT 'table_2' AS table_name, COUNT(*) FROM table_2
UNION
SELECT 'table_3' AS table_name, COUNT(*) FROM table_3
It gives the answers transposed (one row per table instead of ...
How to list imported modules?
...ems():
if isinstance(val, types.ModuleType):
yield val.__name__
This won't return local imports, or non-module imports like from x import y. Note that this returns val.__name__ so you get the original module name if you used import module as alias; yield name instead if you wa...