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A fast method to round a double to a 32-bit int explained
...ly the integers
This follows from the fact that the mantissa is 52 bits wide.
The other interesting fact about adding 251+252 is that it affects the mantissa only in the two highest bits - which are discarded anyway, since we are taking only its lowest 32 bits.
Last but not least: the sign.
I...
How many and which are the uses of “const” in C++?
...
Use const for copy-on-write classes, to make the compiler help you to decide when and when not you need to copy.
struct MyString {
char * getData() { /* copy: caller might write */ return mData; }
char const* getData() const { return mData; }
};
Explanation: You might want to share data...
Python strptime() and timezones?
...umentation now also states the following:
When the %z directive is provided to the strptime() method, an aware datetime object will be produced. The tzinfo of the result will be set to a timezone instance.
Note that this doesn't work with %Z, so the case is important. See the following example...
How to navigate through a vector using iterators? (C++)
...e.
Another advantage of iterators is that it doesn't assume the data is resident in memory; for example, one could create a forward iterator that can read data from an input stream, or that simply generates data on the fly (e.g. a range or random number generator).
Another option using std::for_eac...
Why is list initialization (using curly braces) better than the alternatives?
... integer value cannot be converted to a floating-point type.
Example:
void fun(double val, int val2) {
int x2 = val; // if val==7.9, x2 becomes 7 (bad)
char c2 = val2; // if val2==1025, c2 becomes 1 (bad)
int x3 {val}; // error: possible truncation (good)
char c3 {val2}; // er...
django admin - add custom form fields that are not part of the model
...rms.py you can add a ModelForm class and then declare your extra fields inside that as you normally would. I've also given an example of how you might use these values in form.save():
from django import forms
from yourapp.models import YourModel
class YourModelForm(forms.ModelForm):
extra_fi...
What does “1 line adds whitespace errors” mean when applying a patch?
...y programmers tend to care about. As the manual explains:
What are considered whitespace errors is controlled
by core.whitespace configuration. By default, trailing whitespaces
(including lines that solely consist of whitespaces) and a space
character that is immediately followed by a tab ...
Fixed point vs Floating point number
...read definitions about them all over Google. But none that I have read provide a simple enough explanation of what they really are. Can I get a plain definition with example?
...
Git fast forward VS no fast forward merge
...w us to perform fast forward and no fast fast forward branch merging. Any ideas when to use fast forward merge and when to use no fast forward merge?
...
JSON: why are forward slashes escaped?
... when embedding JSON in a <script> tag, which doesn't allow </ inside strings, like Seb points out.
Some of Microsoft's ASP.NET Ajax/JSON API's use this loophole to add extra information, e.g., a datetime will be sent as "\/Date(milliseconds)\/". (Yuck)
...