Tutorial by Examples: d

(All of these are unstable, and thus can only be used from a nightly compiler.) log_syntax!() #![feature(log_syntax)] macro_rules! logged_sum { ($base:expr) => { { log_syntax!(base = $base); $base } }; ($a:expr, $($rest:expr),+) => { { log_syntax!(a = $...

Fortran 2003 introduced intrinsic modules which provide access to special named constants, derived types and module procedures. There are now five standard intrinsic modules: ISO_C_Binding; supporting C interoperability; ISO_Fortran_env; detailing the Fortran environment; IEEE_Exceptions, IEEE_...

It's good practice to document your work for later use, especially if you are coding for a dynamic workload. Good comments should explain why the code is doing something, not what the code is doing. Function Bonus(EmployeeTitle as String) as Double If EmployeeTitle = "Sales" Then ...

This topic specifically talks about UTF-8 and considerations for using it with a database. If you want more information about using databases in PHP then checkout this topic. Storing Data in a MySQL Database: Specify the utf8mb4 character set on all tables and text columns in your database. ...

JSFiddle: https://jsfiddle.net/UnsungHero97/80qod7aL/ HTML <div class="box_shadow"></div> CSS .box_shadow { -webkit-box-shadow: 0px 0px 10px -1px #444444; -moz-box-shadow: 0px 0px 10px -1px #444444; box-shadow: 0px 0px 10px -1px #444444; }

HTML <div class="box_shadow"></div> CSS .box_shadow { background-color: #1C90F3; width: 200px; height: 100px; margin: 50px; -webkit-box-shadow: inset 0px 0px 10px 0px #444444; -moz-box-shadow: inset 0px 0px 10px 0px #444444; box-shadow: inse...

JSFiddle: https://jsfiddle.net/UnsungHero97/80qod7aL/2/ HTML <div class="box_shadow"></div> CSS .box_shadow { background-color: #1C90F3; width: 200px; height: 100px; margin: 50px; } .box_shadow:after { content: ""; width: 190px; height: ...

The following code will print the arguments to the program, and the code will attempt to convert each argument into a number (to a long): #include <stdlib.h> #include <stdio.h> #include <errno.h> #include <limits.h> int main(int argc, char* argv[]) { for (int ...

-- Create an index for column 'name' in table 'my_table' CREATE INDEX idx_name ON my_table(name);

A unique index prevents the insertion of duplicated data in a table. NULL values can be inserted in the columns that form part of the unique index (since, by definition, a NULL value is different from any other value, including another NULL value) -- Creates a unique index for column 'name' in tabl...

Defining a member block inside a resource creates a route that can act on an individual member of that resource-based route: resources :posts do member do get 'preview' end end This generates the following member route: get '/posts/:id/preview', to: 'posts#preview' # preview_post_p...

The specifier override has a special meaning in C++11 onwards, if appended at the end of function signature. This signifies that a function is Overriding the function present in base class & The Base class function is virtual There is no run time significance of this specifier as is mainl...

A syntactic extension that lets you write \case in place of \arg -> case arg of. Consider the following function definition: dayOfTheWeek :: Int -> String dayOfTheWeek 0 = "Sunday" dayOfTheWeek 1 = "Monday" dayOfTheWeek 2 = "Tuesday" dayOfTheWeek 3 = "W...

:root { --W200: 200px; --W10: 10px; } .Bx2 { width: var(--W200); height: var(--W200); margin: var(--W10); }

Trailing spaces \s*$: This will match any (*) whitespace (\s) at the end ($) of the text Leading spaces ^\s*: This will match any (*) whitespace (\s) at the beginning (^) of the text Remarks \s is a common metacharacter for several RegExp engines, and is meant to capture whitespace characters (...

The <datalist> tag specifies a list of pre-defined options for an <input> element. It provide an "autocomplete" feature on <input> elements. Users will see a drop-down list of options as they write. <input list="Languages"> <datalist id="Langua...

In Python 2, <> is a synonym for !=; likewise, `foo` is a synonym for repr(foo). Python 2.x2.7 >>> 1 <> 2 True >>> 1 <> 1 False >>> foo = 'hello world' >>> repr(foo) "'hello world'" >>> `foo` "'hello world'"...

child.py import time def main(): print "starting work" time.sleep(1) print "work work work work work" time.sleep(1) print "done working" if __name__ == '__main__': main() parent.py import os def main(): for i in range(5):...

This example starts Notepad, waits for it to be closed, then gets its exit code. #include <Windows.h> int main() { STARTUPINFOW si = { 0 }; si.cb = sizeof(si); PROCESS_INFORMATION pi = { 0 }; // Create the child process BOOL success = CreateProcessW( L"C:...

Pass dynamic inventory to ansible-playbook: ansible-playbook -i inventory/dyn.py -l targethost my_playbook.yml python inventory/dyn.py should print out something like this: { "_meta": { "hostvars": { "10.1.0.10": { "ansible_user": ...