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Is optimisation level -O3 dangerous in g++?
I have heard from various sources (though mostly from a colleague of mine), that compiling with an optimisation level of -O3 in g++ is somehow 'dangerous', and should be avoided in general unless proven to be necessary.
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Brew doctor says: “Warning: /usr/local/include isn't writable.”
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Take ownership of it and everything in it.
Mac OS High Sierra or newer: (ty to Kirk in the comments below)
$ sudo chown -R $(whoami) $(brew --prefix)/*
Previous versions of macos:
$ sudo chown -R $USER:admin /usr/local/include
Then do another
$ brew doctor
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Visibility of global variables in imported modules
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Globals in Python are global to a module, not across all modules. (Many people are confused by this, because in, say, C, a global is the same across all implementation files unless you explicitly make it static.)
There are different ways to solve this, depending on your ac...
“Insufficient Storage Available” even there is lot of free space in device memory
... sure Superuser and Terminal Emulator apps are installed. (They come with most custom ROMs.)
Run Terminal Emulator
Type in su, hit return.
This will bring up a Superuser prompt. Grant access. (You will have to wait three seconds before you can click "Allow".)
Change current directory by typing in cd...
Should you commit .gitignore into the Git repos?
...mally yes, .gitignore is useful for everyone who wants to work with the repository. On occasion you'll want to ignore more private things (maybe you often create LOG or something. In those cases you probably don't want to force that on anyone else.
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'^M' character at end of lines
...the SQL script as it is echoed to the command-line. I don't know on which OS the SQL script was originally created.
16 Ans...
When to use NSInteger vs. int
When should I be using NSInteger vs. int when developing for iOS? I see in the Apple sample code they use NSInteger (or NSUInteger ) when passing a value as an argument to a function or returning a value from a function.
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std::string to float or double
...to convert a string to a double.
You can do it with the stringstream or boost::lexical_cast but those come with a performance penalty.
Ahaha you have a Qt project ...
QString winOpacity("0.6");
double temp = winOpacity.toDouble();
Extra note:
If the input data is a const char*, QByteArray::to...
Why do 64-bit DLLs go to System32 and 32-bit DLLs to SysWoW64 on 64-bit Windows?
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The good news is, as an example of Microsoft engineering genius, this is pretty much self-documenting.
– Spike0xff
Dec 21 '12 at 20:08
8
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How to correct TypeError: Unicode-objects must be encoded before hashing?
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To store the password (PY3):
import hashlib, os
password_salt = os.urandom(32).hex()
password = '12345'
hash = hashlib.sha512()
hash.update(('%s%s' % (password_salt, password)).encode('utf-8'))
password_hash = hash.hexdigest()
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