static_cast is the first cast you should attempt to use. It does things like implicit conversions between types (such as int to float, or pointer to void*), and it can also call explicit conversion functions (or implicit ones). In many cases, explicitly stating static_cast isn’t necessary, but it’s important to note that the T(something) syntax … Read more
Setting a bit Use the bitwise OR operator (|) to set a bit. number |= 1UL << n; That will set the nth bit of number. n should be zero, if you want to set the 1st bit and so on upto n-1, if you want to set the nth bit. Use 1ULL if number … Read more
Consider two libraries called Foo and Bar: using namespace foo; using namespace bar; Everything works fine, and you can call Blah() from Foo and Quux() from Bar without problems. But one day you upgrade to a new version of Foo 2.0, which now offers a function called Quux(). Now you’ve got a conflict: Both Foo … Read more
I use this to split string by a delimiter. The first puts the results in a pre-constructed vector, the second returns a new vector. #include <string> #include <sstream> #include <vector> #include <iterator> template <typename Out> void split(const std::string &s, char delim, Out result) { std::istringstream iss(s); std::string item; while (std::getline(iss, item, delim)) { *result++ = … Read more
The compiler is allowed to make one implicit conversion to resolve the parameters to a function. What this means is that the compiler can use constructors callable with a single parameter to convert from one type to another in order to get the right type for a parameter. Here’s an example class with a constructor … Read more
A pointer can be re-assigned: int x = 5; int y = 6; int *p; p = &x; p = &y; *p = 10; assert(x == 5); assert(y == 10); A reference cannot be re-bound, and must be bound at initialization: int x = 5; int y = 6; int &q; // error int &r … Read more