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What is move semantics?

...: #include <cstring> #include <algorithm> class string { char* data; public: string(const char* p) { size_t size = std::strlen(p) + 1; data = new char[size]; std::memcpy(data, p, size); } Since we chose to manage the memory ourselves, we need...
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Is gcc's __attribute__((packed)) / #pragma pack unsafe?

....h> #include <stddef.h> int main(void) { struct foo { char c; int x; } __attribute__((packed)); struct foo arr[2] = { { 'a', 10 }, {'b', 20 } }; int *p0 = &arr[0].x; int *p1 = &arr[1].x; printf("sizeof(struct foo) = %d\n", (int)sizeof(str...
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How do I trim whitespace from a string?

... Hello ") ' Hello' Also, note that str.strip() removes other whitespace characters as well (e.g. tabs and newlines). To remove only spaces, you can specify the character to remove as an argument to strip, i.e.: >>> " Hello\n".strip(" ") 'Hello\n' ...
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“sending 'const NSString *' to parameter of type 'NSString *' discards qualifiers” warning

...he term on its right only if there's nothing on its left side (e. g. const char * and a char const * are non-const pointers to const char, but char *const is a const pointer to non-const char). – user529758 Oct 11 '12 at 4:29 ...
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Why is “while ( !feof (file) )” always wrong?

...e is again std::cin, just as before. POSIX, write(2) to flush a buffer: char const * p = buf; ssize_t n = bufsize; for (ssize_t k = bufsize; (k = write(fd, p, n)) > 0; p += k, n -= k) {} if (n != 0) { /* error, failed to write complete buffer */ } The result we use here is k, the numb...
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Why historically do people use 255 not 256 for database field magnitudes?

You often see database fields set to have a magnitude of 255 characters, what is the traditional / historic reason why? I assume it's something to do with paging / memory limits, and performance but the distinction between 255 and 256 has always confused me. ...
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How to handle Objective-C protocols that contain properties?

...hInteger:(factor*amount)]; } // << @end int main(int argc, const char * argv[]) { @autoreleasepool { Person *duncan=[[Person alloc]initConforming]; duncan.firstname=@"Duncan"; duncan.lastname=@"Smith"; [Viewer printLargeDescription:duncan]; S...
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Regular expression to match URLs in Java

...ckzah|xxx)" + "|y[et]" + "|z[amw]))"; /** * Good characters for Internationalized Resource Identifiers (IRI). * This comprises most common used Unicode characters allowed in IRI * as detailed in RFC 3987. * Specifically, those two byte Unicode characters are ...
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Error “initializer element is not constant” when trying to initialize variable with const

...s_pFooInit = (&(const foo_t){ .a=2, .b=4, .c=6 }); int main (int argc, char **argv) { const foo_t *const f1 = &s_FooInit; const foo_t *const f2 = s_pFooInit; printf("Foo1 = %d, %d, %d\n", f1->a, f1->b, f1->c); printf("Foo2 = %d, %d, %d\n", f2->a, f2->b, f2->...
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Algorithm to return all combinations of k elements from n

... takes an array of letters as an argument and a number of those letters to select. 71 Answers ...