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How do you test functions and closures for equality?
...t = (Int, Int)
let (hi, lo) = unsafeBitCast(f, IntInt.self)
let offset = sizeof(Int) == 8 ? 16 : 12
let ptr = UnsafePointer<Int>(lo+offset)
return (ptr.memory, ptr.successor().memory)
}
@infix func === <A,R>(lhs:A->R,rhs:A->R)->Bool {
let (tl, tr) = (peekFun...
How to do an INNER JOIN on multiple columns
...rts table twice - then you can use both from and to tables in your results set:
SELECT
Flights.*,fromAirports.*,toAirports.*
FROM
Flights
INNER JOIN
Airports fromAirports on Flights.fairport = fromAirports.code
INNER JOIN
Airports toAirports on Flights.tairport = toAirports.code
WHERE...
Could not execute editor
...
Yesterday was just one of those days. On a lark, I decided to set the full path to vi (e.g. /usr/bin/vi) rather than just the executable. Now everything works. I have to admit that I don't get it since vi is perfectly executable on its own (my $EDITOR env variable is also set to vi), bu...
Fastest way to iterate over all the chars in a String
In Java, what would the fastest way to iterate over all the chars in a String, this:
8 Answers
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How to close IPython Notebook properly?
...and commandline? So that people who want the server to always run can just set up the correct config.
– gaborous
Mar 22 '13 at 11:25
7
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Pure virtual function with implementation
...classes to always perform their own work but also be able to call a common set of functionality.
Note that even though it's permitted by the language, it's not something that I see commonly used (and the fact that it can be done seems to surprise most C++ programmers, even experienced ones).
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Why does scanf() need “%lf” for doubles, when printf() is okay with just “%f”?
... editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
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createEditor();
...
How can I format a decimal to always show 2 decimal places?
... method rounds to a fixed number of decimal places. If the Inexact trap is set, it is also useful for validation:
>>> TWOPLACES = Decimal(10) ** -2 # same as Decimal('0.01')
>>> # Round to two places
>>> Decimal('3.214').quantize(TWOPLACES)
Decimal('3.21')
>>&...
Piping command output to tee but also save exit code of command [duplicate]
...
You can set the pipefail shell option option on to get the behavior you want.
From the Bash Reference Manual:
The exit status of a pipeline is the exit status of the last command
in the pipeline, unless the pipefail option is ...
Change all files and folders permissions of a directory to 644/755
...oup.org/onlinepubs/9699919799/utilities/chmod.html).
What this does is:
Set file/directory to r__r__r__ (0444)
Add w for owner, to get rw_r__r__ (0644)
Set execute for all if a directory (0755 for dir, 0644 for file).
Importantly, the step 1 permission clears all execute bits, so step 3 only ad...