Search results
- Dictionaryde·fer/dəˈfər/
verb
- 1. put off (an action or event) to a later time; postpone: "they deferred the decision until February"
Powered by Oxford Dictionaries
Sep 7, 2015 · This implementation is zero-overhead unlike some other answers, as well as syntactically nicer and easier to use. It also has zero dependencies, reducing compile times. You can paste this snippet anywhere in your codebase and it will just work. #ifndef defer. struct defer_dummy {}; template <class F> struct deferrer { F f; ~deferrer() { f(); } };
Jul 1, 2023 · char* c = log_malloc(30); DEFER(log_free, c); POST_DEFER(); test(); return 0; This code works and, in my basic benchmarking compared to just manually ordering the destructor statements, has about a 10% performance overhead. However, it is limited in the number of DEFER macro calls that can be handled.
C++ have them. And C & C++ are very different languages. In C++11, you might define your class, having a std::vector or std::function -s, initialized using a std::initialized_list of lambda expressions (and perhaps dynamically augmented by some push_back). Then its destructor could mimic Go's defer -ed statements.
Apr 30, 2015 · 1. Note that on step 4, the preprocessor doesn't look backward: if say you have a macro that expands to () it doesn't look back to see if there was a macro name preceding this invocation. That's what makes DEFER work. Step #1 (fully replace each argument in isolation) makes EXPAND work. – Igor Tandetnik.
Mar 17, 2021 · Both use same technique and use an object to do the RAII. so the macro (#define) is to declare an "unique" identifier (of the type of their object) to be able to call defer several time in the same function, so after MACRO replacement, it result to something like:
Sep 26, 2021 · In this Modern C video there's a trick that allows to postpone execution of a code until the block/scope exits. It's used as follows: int main() { int foo=0, bar; const char *etc = "Some
163. The real answer is: Because you cannot trust defer. In concept, defer and async differ as follows: async allows the script to be downloaded in the background without blocking. Then, the moment it finishes downloading, rendering is blocked and that script executes. Render resumes when the script has executed.
Mar 17, 2009 · Jul 3, 2013 at 22:38. 1. If you invoke the macro more than once, you need each typedef to be unique. If __COUNTER__ is not available, the failover is to use __LINE__, but that will fail of you have the bad luck of using the macro on the same line in two different source files. – EBlake.
May 9, 2018 · 153. If you want to implement a while loop, you will need to use recursion in the preprocessor. The easiest way to do recursion is to use a deferred expression. A deferred expression is an expression that requires more scans to fully expand: #define EMPTY()
Jun 28, 2010 · Here I thought that the C99 preprocessor was definetely not turing complete.. +1 for thinking out of the box. – Earlz. Aug 11, 2012 at 2:36. 1. +1 Quite a creative way to show that preprocessor can scan symbols on a tape ;-) (Thanks to the mod for accepting the flagging to remove the wiki!).
