C ++引用 - 它们只是语法糖？ [英] C++ references - are they just syntactic sugar?

问题描述

是C ++引用只是语法糖，还是在某些情况下提供任何加速？

Is a C++ reference just syntactic sugar, or does it offer any speed ups in certain cases?

例如，一个call-by-pointer ，并且对于一个调用引用也是如此。基本机制看起来是相同的。

For example, a call-by-pointer involves a copy anyway, and that seems to be true about a call-by-reference as well. The underlying mechanism appears to be the same.

编辑：大约六个答案和许多评论后。我仍然认为参考只是合成糖。

After about six answers and many comments. I am still of the opinion references are just syntatic sugar. If people could answer in a straight yes or no, and if someone could do an accepted answer?

推荐答案

参考文献有更强的保证，而不是指针，所以编译器可以更积极地优化。我最近看到GCC内联多个嵌套调用通过函数引用完美，但没有一个通过函数指针（因为它不能证明指针总是指向同一个函数）。

References have stronger guarantees than pointers, so the compiler can optimize more aggressively. I've recently seen GCC inline multiple nested calls through function references perfectly, but not a single one through function pointers (because it couldn't prove that the pointer was always pointing at the same function).

如果引用结束存储在某处，它通常占用与指针相同的空间。这不是说，再次，它将像一个指针一样使用：如果它知道引用绑定到哪个对象，编译器可能会通过它。

If the reference ends up stored somewhere, it typically takes the same space as a pointer. That is not to say, again, that it will be used like a pointer : the compiler may well cut through it if it knows which object the reference was bound to.

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