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Can I implement an autonomous `self` member type in C++?
...of Foo:
template <typename...Ts>
class Self;
template <typename X, typename...Ts>
class Self<X,Ts...> : public Ts...
{
protected:
typedef X self;
};
#define WITH_SELF(X) X : public Self<X>
#define WITH_SELF_DERIVED(X,...) X : public Self<X,__VA_ARGS__>
class WIT...
What would a “frozen dict” be?
...sh = hash_
return self._hash
It should work great:
>>> x = FrozenDict(a=1, b=2)
>>> y = FrozenDict(a=1, b=2)
>>> x is y
False
>>> x == y
True
>>> x == {'a': 1, 'b': 2}
True
>>> d = {x: 'foo'}
>>> d[y]
'foo'
...
What is the purpose of setting a key in data.table?
...ta.table and there are many functions which require me to set a key (e.g. X[Y] ). As such, I wish to understand what a key does in order to properly set keys in my data tables.
...
Find first element in a sequence that matches a predicate
...
To find first element in a sequence seq that matches a predicate:
next(x for x in seq if predicate(x))
Or (itertools.ifilter on Python 2):
next(filter(predicate, seq))
It raises StopIteration if there is none.
To return None if there is no such element:
next((x for x in seq if predic...
Is multiplication and division using shift operators in C actually faster?
Multiplication and division can be achieved using bit operators, for example
19 Answers
...
Split function equivalent in T-SQL?
... set @iStart = 1
while 1=1
begin
set @iPos = charindex( @cDelimiter, @sString, @iStart )
if @iPos = 0
set @iPos = len( @sString )+1
if @iPos - @iStart > 0
insert into @tParts
values ( substring( @sString, @iStart...
multiple packages in context:component-scan, spring config
How can I add multiple packages in spring-servlet.xml file in context:component-scan element?
8 Answers
...
Why do I need 'b' to encode a string with Base64?
Following this python example , I encode a string as Base64 with:
5 Answers
5
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No increment operator (++) in Ruby? [duplicate]
...
Ruby has no pre/post increment/decrement operator. For instance, x++ or x-- will fail to parse. More importantly, ++x or --x will do nothing! In fact, they behave as multiple unary prefix operators: -x == ---x == -----x == ...... To increment a number, simply write x += 1.
Taken from "Th...
How to copy a selection to the OS X clipboard
I have an area selected in Vim. How can I copy it into the OS X clipboard?
27 Answers
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