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Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
... will attempt to create the database and will fail with possibly confusing error message
– Oliver
Jan 12 at 14:43
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Covariance and contravariance real world example
...iantly as a mammal hat…
IHat<Mammal> mHat = rHat; // Compiler error
// …because…
mHat.hide(new Dolphin()); // Hide a dolphin in a rabbit hat??
// It also cannot be treated contravariantly as a cottontail hat…
IHat<CottonTail> cHat = rHat; // Compiler error
// …becau...
Reimport a module in python while interactive
...as well as the autoreload magic, and I see my code change reflected in the error message's stack, but the error itself still appears to be off the stale code (e.g., the line of the error is on the exact same line as before, which I have changed to a comment, and a comment clearly cannot be causing e...
cannot convert data (type interface {}) to type string: need type assertion
...]i to its value type, we have to do it individually:
// var items []i
for _, item := range items {
value, ok := item.(T)
dosomethingWith(value)
}
Performance
As for performance, it can be slower than direct access to the actual value as show in this stackoverflow answer.
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How to copy data to clipboard in C#
...xception see "Current thread must be set to single thread apartment (STA)" error in copy string to clipboard
This question/answer covers regular .NET, for .NET Core see - .Net Core - copy to clipboard?
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Getting the encoding of a Postgres database
I have a database, and I need to know the default encoding for the database. I want to get it from the command line.
6 Answ...
What's the algorithm to calculate aspect ratio?
...(self.width / common) + ':' + str(self.height / common)
self.ratio_error = 0
# Special case: ratio is not well behaved
if not self.ratio in accepted_ratios:
lesser_error = 999
lesser_index = -1
my_ratio_normalized = float(self.width) / flo...
Laravel Schema onDelete set null
... try
$table->...->onDelete(DB::raw('set null'));
If there are any errors, would also be helpful
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boost::flat_map and its performance compared to map and unordered_map
...ove the overhead of the measurer itself.
u64 g_accuracy;
static u64 const errormeasure = ~((u64)0);
#ifdef _MSC_VER
#pragma intrinsic(__rdtsc)
inline u64 GetRDTSC()
{
int a[4];
__cpuid(a, 0x80000000); // flush OOO instruction pipeline
return __rdtsc();
}
inline void WarmupRDTSC()
{
...
How to get Bitmap from an Uri?
...wallpaper size). getBitmap() calls decodeStream() which fails with the OOM error from stackoverflow.com/questions/2220949/handling-large-bitmaps. Any other advice? MediaStore.Images.Thumbnails.getThumbnail() apparently does not take a contentURI.
– pjv
Jun 3 '1...