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Template function inside template class
...
template <class T>
template <class U>
void MyClass<T>::foo() { /* ... */ }
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Is it possible to roll back CREATE TABLE and ALTER TABLE statements in major SQL databases?
...situations are quite handled- for example, if you try to select from table foo while another transaction is dropping it and creating a replacement table foo, then the blocked transaction will finally receive an error rather than finding the new foo table. (Edit: this was fixed in or before PostgreSQ...
Regular expression to match a word or its prefix
...Start phpsh, put some content into a variable, match on word.
el@apollo:~/foo$ phpsh
php> $content1 = 'badger'
php> $content2 = '1234'
php> $content3 = '$%^&'
php> echo preg_match('(\w+)', $content1);
1
php> echo preg_match('(\w+)', $content2);
1
php> echo preg_match('(\w+...
Sorting list based on values from another list?
...ere looking to sort a list by a list where the values matched.
list_a = ['foo', 'bar', 'baz']
list_b = ['baz', 'bar', 'foo']
sorted(list_b, key=lambda x: list_a.index(x))
# ['foo', 'bar', 'baz']
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Check whether a path is valid in Python without creating a file at the path's target
...s, which frankly bore and anger me in equal measure:
>>> print('"foo.bar" valid? ' + str(is_pathname_valid('foo.bar')))
"foo.bar" valid? True
>>> print('Null byte valid? ' + str(is_pathname_valid('\x00')))
Null byte valid? False
>>> print('Long path valid? ' + str(is_path...
What's the (hidden) cost of Scala's lazy val?
...he bitmap indicates it is necessary.
Using:
class Something {
lazy val foo = getFoo
def getFoo = "foo!"
}
produces sample bytecode:
0 aload_0 [this]
1 getfield blevins.example.Something.bitmap$0 : int [15]
4 iconst_1
5 iand
6 iconst_0
7 if_icmpne 48
10 aload_0 [this]
11 dup
12...
Separation of JUnit classes into special test package?
...they test, but in a different physical directory, like:
myproject/src/com/foo/Bar.java
myproject/test/com/foo/BarTest.java
In a Maven project it would look like this:
myproject/src/main/java/com/foo/Bar.java
myproject/src/test/java/com/foo/BarTest.java
The main point in this is that my test cl...
How do I copy a hash in Ruby?
...at clone of a hash makes a shallow copy. That is to say:
h1 = {:a => 'foo'}
h2 = h1.clone
h1[:a] << 'bar'
p h2 # => {:a=>"foobar"}
What's happening is that the hash's references are being copied, but not the objects that the references refer to.
If you want a deep...
How to hash a string into 8 digits?
... invocations. See here:
$ python -V
Python 2.7.5
$ python -c 'print(hash("foo"))'
-4177197833195190597
$ python -c 'print(hash("foo"))'
-4177197833195190597
$ python3 -V
Python 3.4.2
$ python3 -c 'print(hash("foo"))'
5790391865899772265
$ python3 -c 'print(hash("foo"))'
-8152690834165248934
This...
Why does git revert complain about a missing -m option?
...
Say the other guy created bar on top of foo, but you created baz in the meantime and then merged, giving a history of
$ git lola
* 2582152 (HEAD, master) Merge branch 'otherguy'
|\
| * c7256de (otherguy) bar
* | b7e7176 baz
|/
* 9968f79 foo
Note: git lola i...