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Performance optimization strategies of last resort [closed]
...tors of floats. Changing the code to carry around the extra empty slot and converting the calculation to floating point from fixed point allowed for a slightly less-accurate but much faster result.
– RBerteig
May 30 '09 at 2:19
...
What are transparent comparators?
...ned, existing code may pass through objects directly which would have been converted without the member templates. The example use-case from n3657 is locating an object in a std::set<std::string> using a string literal: with the C++11 definition a std::string object is constructed when passing...
urlencode vs rawurlencode?
...oes things the old school way, where + meant "space."
If you're trying to convert between the old format and new formats, be sure that your code doesn't goof up and turn something that's a decoded + sign into a space by accidentally double-encoding, or similar "oops" scenarios around this space/20%...
How to measure time in milliseconds using ANSI C?
...y, so if you have a ticks value and the frequency is known, you can easily convert ticks to elapsed time. It is actually not guaranteed that a monotonic clock reflects the current system time in any way, it may also count ticks since a system startup. But it guarantees that a clock is always run up ...
What's invokedynamic and how do I use it?
...ions on the types of values supplied to its operations (e.g. Java)
Weak - converts (casts) arguments of an operation if those arguments have incompatible types (e.g. Visual Basic)
Knowing that Java is a Statically and Weakly typed, how do you implement Dynamically and Strongly typed languages on t...
What are bitwise shift (bit-shift) operators and how do they work?
...d together makes 320:
(row * 320) = (row * 256) + (row * 64)
Now we can convert that into left shifts:
(row * 320) = (row << 8) + (row << 6)
For a final result of:
memoryOffset = ((row << 8) + (row << 6)) + column
Now we get the same offset as before, except instead ...
Node.js vs .Net performance
...n other platforms, but on Windows IIS is the winner. Developers looking to convert their ASP.NET MVC to nodejs should pause and think twice before proceeding.
Updated (5/17/2012)
Tomcat (on windows) seems to beat IIS hands down, about 3 times faster than IIS in dishing out static html.
tomcat
ind...
How are virtual functions and vtable implemented?
...a vtable
Foo z = arg; // copy constructor Foo::Foo(const Foo&) will convert to Foo
z.a(); // non-virtual Foo::a, since z is a Foo, even if arg was not
}
The steps the hardware has to take are essentially the same, no matter whether the function is overwritten or not. The address of...
How to import multiple .csv files at once?
...
Here are some options to convert the .csv files into one data.frame using R base and some of the available packages for reading files in R.
This is slower than the options below.
# Get the files names
files = list.files(pattern="*.csv")
# First ap...
Why is “while ( !feof (file) )” always wrong?
...he result we must use is the return value of scanf, the number of elements converted.
C++, iostreams formatted extraction:
for (int n; std::cin >> n; ) {
consume(n);
}
The result we must use is std::cin itself, which can be evaluated in a boolean context and tells us whether the ...