Web某些源代码中鼓励用 std::endl 代替 '\n' ，这可能显著地降低输出性能。 多数实现中，标准输出是行缓冲的，而写入 '\n' 就会导致冲入，除非执行 std::ios::sync_with_stdio(false) 。 这些情形中，不必要的 endl 只会降低文件输出的性能，而非标准输出的。 此维基上的代码示例 遵循 Bjarne Stroustrup 和 《 C++ 核心方针》 ，只在需要时冲入标准输出。 需要冲入不完 … WebUnless std::ios_base::sync_with_stdio(false) has been issued, it is safe to concurrently access these objects from multiple threads for both formatted and unformatted output. By specification of std::cin, std::cin.tie() returns &std::cout.
c++ - Is cout synchronized/thread-safe? - Stack Overflow
Webios::sync_with_stdio (false) From the second resource: This disables the synchronization between the C and C++ standard streams. By default, all standard streams are synchronized, which in practice allows you to mix C- and C++-style I/O … room sharing near by norwood ohio
std::ios_base:: sync_with_stdio - Reference
WebThere can be good reasons not to, but your default should be std::cout. You can improve the performance of std::cout by calling std::ios::sync_with_stdio (false). [ 1] This allows std::cout to manage its own buffering independently of what C stdio functions would use, resulting in more efficient operation. This is a global action. WebAug 14, 2014 · When std::cout is constructed, it uses the stream buffer associated with the object stdout, declared in . By default, operations on std::cout can be freely mixed with output functions like std::printf (). In practical terms, synchronization usually means that a standard iostream object and a standard stdio object share a buffer. WebBy default, cout is synchronized with stdout (see ios_base::sync_with_stdio). A program should not mix output operations on cout with output operations on wcout (or with other … room sheets