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Hash collision in git
...m is so staggeringly small you can ignore this issue
"But when a collision does occur, then what actually happens?"
Ok, suppose the improbable does happen, or suppose someone managed to tailor a deliberate SHA-1 hash collision. What happens then?
In that case there is an excellent answer where someo...
How to change a nullable column to not nullable in a Rails migration?
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Actually, according to the Rails 4.2 docs, the 4th param does NOT set a default value for future records: "The method accepts an optional fourth argument to replace existing +NULL+s with some other value. Please note the fourth argument does not set a column’s default."
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What is the 'instanceof' operator used for in Java?
...supertype of Dog and possibly less "refined".
And,
dog instanceof Cat // does not even compile!
This is because Dog is neither a subtype nor a supertype of Cat, and it also does not implement it.
Note that the variable used for dog above is of type Object. This is to show instanceof is a runtim...
How to add screenshot to READMEs in github repository?
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I'm interested how long images loaded this way will live. Does github perform some images cleanup? Like, "if this image not referenced from any github issue, I can safely remove it"...
– artin
Aug 7 '17 at 1:09
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Is there a shortcut to move between header and source file in VC++?
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does anyone have a solution for VS2013?
– Shaun Rowan
Nov 19 '13 at 3:00
5
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html tables: thead vs th
...u object to someone linking to a 30 year old RFC that's still in use? What does it matter how old the page is so long as the information is still relevant?
– jmbpiano
Oct 16 '17 at 15:08
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css transform, jagged edges in chrome
...sing transition instead of transform, -webkit-backface-visibility: hidden; does not work. A jagged edge appears during animation for a transparent png file.
To solve it I used: outline: 1px solid transparent;
share
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Replace whole line containing a string using Sed
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@MarcusDowning GNU sed does not require the space; it works just fine as originally posted. If your particular sed requires the space, then by all means note which sed is incompatible and add the necessary invocation as a comment. However, please d...
Rails create or update magic?
...ver this functionality.
Model.upsert(column_name: value)
[upsert] It does not instantiate any models nor does it trigger Active Record callbacks or validations.
Rails 5, 4, and 3
Not if you are looking for an "upsert" (where the database executes an update or an insert statement in the sam...
0.1 float is greater than 0.1 double. I expected it to be false [duplicate]
... comments have said, IEEE754, the de-facto standard on FP representations, does it this way, but in theory there could be FP implementations that simply truncated instead of rounding.
– us2012
Oct 10 '13 at 14:18
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