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define() vs. const

... a static scalar (number, string or other constant like true, false, null, __FILE__), whereas define() takes any expression. Since PHP 5.6 constant expressions are allowed in const as well: const BIT_5 = 1 << 5; // Valid since PHP 5.6 and invalid previously define('BIT_5', 1 << 5); /...
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How to get the error message from the error code returned by GetLastError()?

...rror message has been recorded LPSTR messageBuffer = nullptr; size_t size = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, errorMessageID, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&a...
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TypeError: Missing 1 required positional argument: 'self'

...p.getPumps() Small example - >>> class TestClass: def __init__(self): print("in init") def testFunc(self): print("in Test Func") >>> testInstance = TestClass() in init >>> testInstance.testFunc() in Test Func ...
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What are the details of “Objective-C Literals” mentioned in the Xcode 4.4 release notes?

... This part is new. Expression Literals When you have an expression (M_PI / 16 for example) you should put it inside parenthesis. This syntax works for numeral expressions, booleans, finding an index in a (C-) string, boolean values, enum constants, and even character strings! NSNumber *piO...
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How to toggle a value in Python

...; toggle() 'blue' Note that in Python 3 the next() method was changed to __next__(), so the first line would be now written as toggle = itertools.cycle(['red', 'green', 'blue']).__next__ share | i...
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Writing your own STL Container

...seudo-container I pieced together from § 23.2.1\4 Note that the iterator_category should be one of std::input_iterator_tag, std::output_iterator_tag,std::forward_iterator_tag,std::bidirectional_iterator_tag,std::random_access_iterator_tag. Also note that the below is technically more strict than ...
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How to remove from a map while iterating it?

...begin(); it != m.cend() /* not hoisted */; /* no increment */) { if (must_delete) { m.erase(it++); // or "it = m.erase(it)" since C++11 } else { ++it; } } Note that we really want an ordinary for loop here, since we are modifying the container itself. The range-based loop sh...
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Finding all possible combinations of numbers to reach a given sum

...t those that reach the target. Here is the algorithm in Python: def subset_sum(numbers, target, partial=[]): s = sum(partial) # check if the partial sum is equals to target if s == target: print "sum(%s)=%s" % (partial, target) if s >= target: return # if we re...
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What are rvalues, lvalues, xvalues, glvalues, and prvalues?

... three: lvalue, xvalue, prvalue. A Venn diagram would look like this: ______ ______ / X \ / / \ \ | l | x | pr | \ \ / / \______X______/ gl r Examples with functions: int prvalue(); int& lvalue(); int&& xvalue(); But al...
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Get bitcoin historical data [closed]

...ocket in higher resolution over longer time period you could use script log_bitstamp_trades.py below. The script uses python websocket-client and pusher_client_python libraries, so install them. #!/usr/bin/python import pusherclient import time import logging import sys import datetime import sig...