C++ lambda 函数可以递归吗？
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Can lambda functions be recursive?
提问by fredoverflow
Possible Duplicate:
Recursive lambda functions in c++0x
可能的重复：
c++0x 中的递归 lambda 函数
Here is a plain old recursive function:
这是一个普通的旧递归函数：
int fak(int n)
{
return (n <= 1) ? 1 : n * fak(n - 1);
}
How would I write such a recursive function as a lambda function?
我将如何编写这样的递归函数作为 lambda 函数？
[](int n) { return (n <= 1) ? 1 : n * operator()(n - 1); }
// error: operator() not defined
[](int n) { return (n <= 1) ? 1 : n * (*this)(n - 1); }
// error: this wasn't captured for this lambda function
Is there any expression that denotes the current lambda so it can call itself recursively?
是否有任何表示当前 lambda 的表达式，以便它可以递归地调用自己？
回答by Andy Prowl
Yes, they can. You can store it in a variable and reference that variable (although you cannot declare the type of that variable as auto, you would have to use an std::functionobject instead). For instance:
是的他们可以。您可以将它存储在一个变量中并引用该变量（尽管您不能将该变量的类型声明为auto，但您必须改用一个std::function对象）。例如：
std::function<int (int)> factorial = [&] (int i)
{
return (i == 1) ? 1 : i * factorial(i - 1);
};
Otherwise, no, you cannot refer the thispointer from inside the body of the lambda.
否则，不，您不能this从 lambda 的主体内部引用指针。
