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What is the worst real-world macros/pre-processor abuse you've ever come across?

...efine static #define void int #define main(x) main() struct F{void println(char* s){std::cout << s << std::endl;}}; struct S{F out;}; public static void main(String[] args) { System.out.println("Hello World!"); } Challenge: Can anyone do it with fewer defines and structs? ;-) ...
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How does the Comma Operator work

...’t work since then the compiler just sees the comma operator between two char[], which cannot be overloaded. The code intentionally first calls the operator= and then subsequently operator, for each remaining element. – Konrad Rudolph Oct 9 '11 at 11:04 ...
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DropDownList in MVC 4 with Razor

... @{ List<SelectListItem> listItems= new List<SelectListItem>(); listItems.Add(new SelectListItem { Text = "Exemplo1", Value = "Exemplo1" }); listItems.Add(new SelectListItem {...
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Can we have multiple “WITH AS” in single sql - Oracle SQL

... You can do this as: WITH abc AS( select FROM ...) , XYZ AS(select From abc ....) /*This one uses "abc" multiple times*/ Select From XYZ.... /*using abc, XYZ multiple times*/ ...
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postgresql list and order tables by size

... select table_name, pg_relation_size(quote_ident(table_name)) from information_schema.tables where table_schema = 'public' order by 2 This shows you the size of all tables in the schema public if you have multiple schemas, y...
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How to read a file into a variable in shell?

...ther answers so far: Trailing newline removal from command expansion NUL character removal Trailing newline removal from command expansion This is a problem for the: value="$(cat config.txt)" type solutions, but not for read based solutions. Command expansion removes trailing newlines: S="...
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PostgreSQL function for last inserted ID

...e: INSERT INTO persons (lastname,firstname) VALUES ('Smith', 'John'); SELECT currval('persons_id_seq'); The name of the sequence must be known, it's really arbitrary; in this example we assume that the table persons has an id column created with the SERIAL pseudo-type. To avoid relying on thi...
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PostgreSQL - fetch the row which has the Max value for a column

...sted index lookup into lives - on my machine -- the latter query plan was selected given my memory settings and -- histogram SELECT l1.* FROM lives AS l1 INNER JOIN ( SELECT usr_id, MAX(time_stamp) AS time_stamp_max FROM lives GROUP BY usr_id ) AS l2 ...
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Allow user to select camera or gallery for image

... How to launch a single Intent to select images from either the Gallery or the Camera, or any application registered to browse the filesystem. Rather than creating a Dialog with a list of Intent options, it is much better to use Intent.createChooser in order...
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OceanBase使用libeasy原理源码分析:客户端 - 数据库(内核) - 清泛网 - 专...

...个session只封装一个请求 easy_request_t r; char data[0]; }; libeasy作为客户端时,将每个发往libeasy服务器端的请求包封装成一个session(easy_session_t),客户端将这个session放入连接的队列中然后返回,随后...