Tutorial by Examples: p

You cannot pass a reference (or const reference) directly to a thread because std::thread will copy/move them. Instead, use std::reference_wrapper: void foo(int& b) { b = 10; } int a = 1; std::thread thread{ foo, std::ref(a) }; //'a' is now really passed as reference thread.join()...

std::this_thread is a namespace which has functions to do interesting things on the current thread from function it is called from. FunctionDescriptionget_idReturns the id of the threadsleep_forSleeps for a specified amount of timesleep_untilSleeps until a specific timeyieldReschedule running threa...

When local changes are present, the git pull command aborts reporting : error: Your local changes to the following files would be overwritten by merge In order to update (like svn update did with subversion), you can run : git stash git pull --rebase git stash pop A convenient way coul...

The STUFF() function inserts a string into another string by first deleting a specified number of characters. The following example, deletes "Svr" and replaces it with "Server". This happens by specifying the start_position and length of the replacement. SELECT STUFF('SQL Svr D...

This example demonstrates how Angular expressions are evaluated when using type="text" and type="number" for the input element. Consider the following controller and view: Controller var app = angular.module('app', []); app.controller('ctrl', function($scope) { $sco...

django-admin is a command line tool that ships with Django. It comes with several useful commands for getting started with and managing a Django project. The command is the same as ./manage.py , with the difference that you don't need to be in the project directory. The DJANGO_SETTINGS_MODULE envir...

You can create an HTML`...` template string tag function to automatically encodes interpolated values. (This requires that interpolated values are only used as text, and may not be safe if interpolated values are used in code such as scripts or styles.) class HTMLString extends String { static e...

// Java: String joined = things.stream() .map(Object::toString) .collect(Collectors.joining(", ")); // Kotlin: val joined = things.joinToString() // ", " is used as separator, by default

// Java: int total = employees.stream() .collect(Collectors.summingInt(Employee::getSalary))); // Kotlin: val total = employees.sumBy { it.salary }

// Java: Map<Department, List<Employee>> byDept = employees.stream() .collect(Collectors.groupingBy(Employee::getDepartment)); // Kotlin: val byDept = employees.groupBy { it.department }

// Java: Map<Department, Integer> totalByDept = employees.stream() .collect(Collectors.groupingBy(Employee::getDepartment, Collectors.summingInt(Employee::getSalary))); // Kotlin: val totalByDept = employees.groupBy { it.dept }.mapValues { it.v...

// Java: Map<Boolean, List<Student>> passingFailing = students.stream() .collect(Collectors.partitioningBy(s -> s.getGrade() >= PASS_THRESHOLD)); // Kotlin: val passingFailing = students.partition { it.grade >= PASS_THRESHOLD }

// Java: Map<Person.Sex, List<String>> namesByGender = roster.stream().collect( Collectors.groupingBy( Person::getGender, Collectors.mapping( Person::getName, Collectors.toList()))); // ...

// Java: Arrays.stream(new int[] {1, 2, 3}) .map(n -> 2 * n + 1) .average() .ifPresent(System.out::println); // 5.0 // Kotlin: arrayOf(1,2,3).map { 2 * it + 1}.average().apply(::println)

// Java: Stream.of("a1", "a2", "a3") .map(s -> s.substring(1)) .mapToInt(Integer::parseInt) .max() .ifPresent(System.out::println); // 3 // Kotlin: sequenceOf("a1", "a2", "a3") .map { it.substring(1) } ...

// Java: IntStream.range(1, 4) .mapToObj(i -> "a" + i) .forEach(System.out::println); // a1 // a2 // a3 // Kotlin: (inclusive range) (1..3).map { "a$it" }.forEach(::println)

// Java: Stream.of(1.0, 2.0, 3.0) .mapToInt(Double::intValue) .mapToObj(i -> "a" + i) .forEach(System.out::println); // a1 // a2 // a3 // Kotlin: sequenceOf(1.0, 2.0, 3.0).map(Double::toInt).map { "a$it" }.forEach(::println)

// Java: long count = items.stream().filter( item -> item.startsWith("t")).count(); // Kotlin: val count = items.filter { it.startsWith('t') }.size // but better to not filter, but count with a predicate val count = items.count { it.startsWith('t') }

// Java: List<String> myList = Arrays.asList("a1", "a2", "b1", "c2", "c1"); myList.stream() .filter(s -> s.startsWith("c")) .map(String::toUpperCase) .sorted() .forEach(System.out::println); // C1 ...

// Java: String phrase = persons .stream() .filter(p -> p.age >= 18) .map(p -> p.name) .collect(Collectors.joining(" and ", "In Germany ", " are of legal age.")); System.out.println(phrase); // In Germany Max and Peter a...