temporary

I'm working on a event tracking system which uses a handful of lookup tables as well as the primary logging table. In a report I'm writing, an object can be selected to view statistics against. The interface shows all objects in order of decreasing importance (ie, hits). The schema for the two tables (slightly trimmed down, but you get the gist): CREATE TABLE IF NOT EXISTS `event_log` ( `event_id` int(11) NOT NULL AUTO_INCREMENT, `user_id` int(5) DEFAULT NULL, `object_id` int(5) DEFAULT NULL, `event_date` datetime DEFAULT NULL, PRIMARY KEY (`event_id`), KEY `user_id` (`user_id`), KEY `object

I heard the temporary objects can only be assigned to constant references. But this code gives error #include <iostream.h> template<class t> t const& check(){ return t(); //return a temporary object } int main(int argc, char** argv){ const int &resCheck = check<int>(); /* fine */ typedef int& ref; const ref error = check<int>(); / *error */ return 0; } The error that is get is invalid initialization of reference of type 'int&' from expression of type 'const int' This: typedef int& ref; const ref error; Doesn't do what you think it does. Consider instead: typedef int* pointer; typedef const

While debugging crash in a multithreaded application I finally located the problem in this statement: CSingleLock(&m_criticalSection, TRUE); Notice that it is creating an unnamed object of CSingleLock class and hence the critical section object gets unlocked immediately after this statement. This is obviously not what the coder wanted. This error was caused by a simple typing mistake. My question is, is there someway I can prevent the temporary object of a class being created at the compile time itself i.e. the above type of code should generate a compiler error. In general, I think whenever a

Coming from C++, I'm rather surprised that this code is valid in Rust: let x = &mut String::new(); x.push_str("Hello!"); In C++, you can't take the address of a temporary, and a temporary won't outlive the expression it appears in. How long does the temporary live in Rust? And since x is only a borrow, who is the owner of the string? Why is it legal to borrow a temporary? It's legal for the same reason it's illegal in C++ — because someone said that's how it should be . How long does the temporary live in Rust? And since x is only a borrow, who is the owner of the string? The reference says :