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Why can't (or doesn't) the compiler optimize a predictable addition loop into a multiplication?
...
The compiler can't generally transform
for (int c = 0; c < arraySize; ++c)
if (data[c] >= 128)
for (int i = 0; i < 100000; ++i)
sum += data[c];
into
for (int c = 0; c < arraySize; ++c)
if (data[c] >= 12...
Behaviour of increment and decrement operators in Python
...e applied on a variable (like ++count ). It compiles, but it does not actually change the value of the variable!
9 Answers...
Is it expensive to use try-catch blocks even if an exception is never thrown?
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try has almost no expense at all. Instead of doing the work of setting up the try at runtime, the code's metadata is structured at compile time such that when an exception is thrown, it now does a relatively expensive operation of walking up the stack an...
Trouble comparing time with RSpec
...olution. I think it's easier and more reliable to just create the date manually:
it "updates updated_at attribute" do
freezed_time = Time.utc(2015, 1, 1, 12, 0, 0) #Put here any time you want
Timecop.freeze(freezed_time) do
patch :update
@article.reload
expect(@article.updated_at).t...
How to efficiently count the number of keys/properties of an object in JavaScript?
...t only iterates through the object but also creates a whole new array with all its keys, so it completely fails at answering the question.
– GetFree
Jun 22 '12 at 14:28
43
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Override Python's 'in' operator?
...am creating my own class in Python, what function should I define so as to allow the use of the 'in' operator, e.g.
3 Answe...
#1071 - Specified key was too long; max key length is 1000 bytes
...tle have been answered before, but please do read on. I've read thoroughly all the other questions/answers on this error before posting.
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How to test code dependent on environment variables using JUnit?
... value);
}
}
For Java 5 to 7 the library System Rules has a JUnit rule called EnvironmentVariables.
import org.junit.contrib.java.lang.system.EnvironmentVariables;
public class EnvironmentVariablesTest {
@Rule
public final EnvironmentVariables environmentVariables
= new EnvironmentVariab...
Does Javascript pass by reference? [duplicate]
...m very confused about my parameter for the rectangle function. It is actually undefined , and redefined inside the function. There are no original reference. If I remove it from the function parameter, the inside area function is not able to access it.
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What does the C++ standard state the size of int, long type to be?
... value of the CHAR_BIT macro that defines the number of bits in a byte. In all but the most obscure platforms it's 8, and it can't be less than 8.
One additional constraint for char is that its size is always 1 byte, or CHAR_BIT bits (hence the name). This is stated explicitly in the standard.
The C...