我想知道是否可以编写一个函数来返回一个lambda函数在C ++ 11。当然一个问题是如何声明这样的函数。每个lambda都有一个类型,但该类型在C ++中不可表达。我不认为这会工作:
I wonder if it's possible to write a function that returns a lambda function in C++11. Of course one problem is how to declare such function. Each lambda has a type, but that type is not expressible in C++. I don't think this would work:
auto retFun() -> decltype ([](int x) -> int) { return [](int x) { return x; } }也不是这样:
int(int) retFun();我不知道从lambdas到例如指向函数的指针的自动转换,这样。是唯一的解决方案手工制作一个函数对象并返回吗?
I'm not aware of any automatic conversions from lambdas to, say, pointers to functions, or some such. Is the only solution handcrafting a function object and returning it?
推荐答案您不需要手工制作的函数对象,只需使用 std :: function ,其中lambda函数可以转换:
You don't need a handcrafted function object, just use std::function, to which lambda functions are convertible:
std::function<int (int)> retFun() { return [](int x) { return x; }; }更多推荐
返回lambda表达式的函数
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