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Performance difference for control structures 'for' and 'foreach' in C#

... of method Test::IterateOverList The compiler treats arrays differently, converting a foreach loop basically to a for loop, but not List<T>. Here's the equivalent code for an array: static void IterateOverArray(object[] array) { foreach (object o in array) { Console.WriteLin...
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How do I select a random value from an enumeration?

... object value= values.GetValue(RNG.Next(values.Length)); return (T)Convert.ChangeType(value, type); } } Usage example: System.Windows.Forms.Keys randomKey = RandomEnum<System.Windows.Forms.Keys>(); sha...
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When should you use 'friend' in C++?

...nt this compiler error: error C2440: '<function-style-cast>': cannot convert from 'utils::f::int_type' to 'utils::f' note: No constructor could take the source type, or constructor overload resolution was ambiguous – Damian Mar 29 '16 at 7:06 ...
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Why is volatile needed in C?

...er is allowed to notice the loop body does not touch the quit variable and convert the loop to a while (true) loop. Even if the quit variable is set on the signal handler for SIGINT and SIGTERM; the compiler has no way to know that. However, if the quit variable is declared volatile, the compiler i...
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Android: Getting a file URI from a content URI?

... cover cursor null cases & conversion from content:// to file:// To convert file, read&write the file from gained uri public static Uri getFilePathFromUri(Uri uri) throws IOException { String fileName = getFileName(uri); File file = new File(myContext.getExternalCacheDir(), fileN...
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How to debug a GLSL shader?

...sinf(x) // undefined otherwise float significand(float x) { // converting int to float so that exp2(genType) gets correctly-typed value float expo=float(floorLog2(abs(x))); return abs(x)/exp2(expo); } // Input: x\in
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store and retrieve a class object in shared preference

... we can use Outputstream to output our Object to internal memory. And convert to string then save in preference. For example: mPrefs = getPreferences(MODE_PRIVATE); SharedPreferences.Editor ed = mPrefs.edit(); ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream(); ...
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std::cin input with spaces?

...(and tweak accordingly for multi-word input), or use getline and lexically convert to int after-the-fact. share | improve this answer | follow | ...
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Obfuscated C Code Contest 2006. Please explain sykes2.c

...amp;8)|i/64]/(i&2?1:8)%8; putchar(32 | (b & 1)); } } Converting the recursion to a loop and sneaking in a bit more simplification: // please don't pass any command-line arguments main() { int i; for(i=447; i>=0; i--) { if(i % 64 == 0) { putchar('...
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Python argparse: default value or specified value

...r-1 arguments const=1 sets the default when there are 0 arguments type=int converts the argument to int If you want test.py to set example to 1 even if no --example is specified, then include default=1. That is, with parser.add_argument('--example', nargs='?', const=1, type=int, default=1) th...