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Why do C and C++ compilers allow array lengths in function signatures when they're never enforced?
...actually ignored.
The decision to allow this syntax was made in the 1970s and has caused much confusion ever since...
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How do you delete an ActiveRecord object?
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It's destroy and destroy_all methods, like
user.destroy
User.find(15).destroy
User.destroy(15)
User.where(age: 20).destroy_all
User.destroy_all(age: 20)
Alternatively you can use delete and delete_all which won't enforce :before_destro...
Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
I'm having a little trouble understanding the pass-by-reference properties of data.table . Some operations seem to 'break' the reference, and I'd like to understand exactly what's happening.
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Can we write our own iterator in Java?
If I have a list containing [alice, bob, abigail, charlie] and I want to write an iterator such that it iterates over elements that begin with 'a', can I write my own ? How can I do that ?
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Converting file size in bytes to human-readable string
...nary, so to express 1551859712 as ~1.4GiB would be correct.
On the other hand, hard disk manufacturers like to use decimal, so they would call it ~1.6GB.
And just to be confusing, floppy disks use a mixture of the two systems - their 1MB is actually 1024000 bytes.
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Why is it impossible to build a compiler that can determine if a C++ function will change the value
...er any given program will terminate. This is known as the halting problem, and it's one of those things that's not computable.
To be clear, you can write a compiler that can determine that a function does change the variable in some cases, but you can't write one that reliably tells you that the fu...
When should the xlsm or xlsb formats be used?
... (in particular, .xlsx , .xlsm , .xlsb ). I've got no problem to understand the use and purpose of .xlsx format but I am still wondering whether we should use a .xlsm or a .xlsb format when creating a file containing some VBA.
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How to go about formatting 1200 to 1.2k in java
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Here is a solution that works for any long value and that I find quite readable (the core logic is done in the bottom three lines of the format method).
It leverages TreeMap to find the appropriate suffix. It is surprisingly more efficient than a previous solution I wrote t...
Multiple linear regression in Python
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Here is a little work around that I created. I checked it with R and it works correct.
import numpy as np
import statsmodels.api as sm
y = [1,2,3,4,3,4,5,4,5,5,4,5,4,5,4,5,6,5,4,5,4,3,4]
x = [
[4,2,3,4,5,4,5,6,7,4,8,9,8,8,6,6,5,5,5,5,5,5,5],
[4,1,2,3,4,5,6,7,5,8,7,8,7,8,7,8,7,...
C++ Build Systems - What to use? [closed]
...looking at starting a new project in C++ - just in my own time initially - and I'm investigating the build systems that are available. It would appear that the answer is "Many, and they're all awful".
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