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Recursive lambda functions in C++11
...r, not by capture.
const auto sum = [term,next](int a, int b) {
auto sum_impl=[term,next](int a,int b,auto& sum_ref) mutable {
if(a>b){
return 0;
}
return term(a) + sum_ref(next(a),b,sum_ref);
};
return sum_impl(a,b,sum_impl);
};
All problems in computer science can...
namespaces for enum types - best practices
...m
{
Red,
Blue,
Green,
Yellow
} enum_type;
private:
enum_type _val;
public:
Color(enum_type val = Blue)
: _val(val)
{
assert(val <= Yellow);
}
operator enum_type() const
{
return _val;
}
};
void SetPenC...
Disable all table constraints in Oracle
...m SQL*Plus or put this thing into a package or procedure. The join to USER_TABLES is there to avoid view constraints.
It's unlikely that you really want to disable all constraints (including NOT NULL, primary keys, etc). You should think about putting constraint_type in the WHERE clause.
BEGIN
...
How do I merge a git tag onto a branch
...
You mean this?
git checkout destination_branch
git merge tag_name
share
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How do I use NSTimer?
...ewController
double timerInterval = 1.0f;
- (NSTimer *) timer {
if (!_timer) {
_timer = [NSTimer timerWithTimeInterval:timerInterval target:self selector:@selector(onTick:) userInfo:nil repeats:YES];
}
return _timer;
}
- (void)viewDidLoad
{
[super viewDidLoad];
[[NSRu...
Formatting code snippets for blogging on Blogger [closed]
...code" class="brush: erlang"><![CDATA[
-module(trim).
-export([string_strip_right/1, reverse_tl_reverse/1, bench/0]).
bench() -> [nbench(N) || N <- [1,1000,1000000]].
nbench(N) -> {N, bench(["a" || _ <- lists:seq(1,N)])}.
bench(String) ->
{{string_strip_right,
lists:s...
Pandas aggregate count distinct
...
How about either of:
>>> df
date duration user_id
0 2013-04-01 30 0001
1 2013-04-01 15 0001
2 2013-04-01 20 0002
3 2013-04-02 15 0002
4 2013-04-02 30 0002
>>> df.groupby("date").agg({"duration": np.sum, "use...
Applying a function to every row of a table using dplyr?
...f Hadley's examples using pmap:
iris %>%
mutate(Max.Len= purrr::pmap_dbl(list(Sepal.Length, Petal.Length), max))
Using this approach, you can give an arbitrary number of arguments to the function (.f) inside pmap.
pmap is a good conceptual approach because it reflects the fact that when ...
Python: using a recursive algorithm as a generator
...],string[:i]+string[i+1:] pairs. Then it would be: for letter,rest in first_letter_options(string): for perm in getPermuations(rest): yield letter+perm
– Thomas Andrews
Oct 14 '16 at 19:04
...
Why can't yield return appear inside a try block with a catch?
...ck");
}
Console.WriteLine("Post");
into (sort of pseudo-code):
case just_before_try_state:
try
{
Console.WriteLine("a");
}
catch (Something e)
{
CatchBlock();
goto case post;
}
__current = 10;
return true;
case just_after_yield_return:
...