C ++模板实例化，究竟是什么意思？(C++ template instantiation, what exactly does it mean?)

 现在，我熟悉模板，我对SFINAE这样的东西有点熟悉，而且我一直想知道编译器实例化模板时会发生什么。 
 
 当您在TMP中执行操作时，如SFINAE，甚至是TMP中的简单Fibonacci序列， 看起来编译器在模板实例化方面所做的工作比我理解的要多。 似乎编译器正在执行模板代码。 
 
 我的问题是， 模板实例化到底是什么，以及编译器实际执行代码时绘制的线在哪里？ 
 
 编译器创建了一个模板类型，是我对模板实例化的理解。 但是在TMP中，似乎它做的远不止于此，这让我感到困惑。 

Now, I'm familiar with templates and I'm somewhat familiar with things like SFINAE, and I've been wondering what goes on when a template is instantiated by the compiler.
 
When you do things in TMP, like SFINAE, or even the simple Fibonacci sequence in TMP, it seems like the compiler is doing more than what I understand under template instantiation. It seems the compiler is executing the template code.
 
My question is, what exactly is template instantiation and where is the line drawn with the compiler actually executing code? 
 
The compiler creates a type of your template, is my understanding of template instantiation. But in TMP it seems like it's doing a whole lot more than that, and that confuses me. 

原文：https://stackoverflow.com/questions/10508321