将功能模板传递给其他功能 [英] Pass a function template to other function

问题描述

假设我有一个函数可以对任意容器类型(C ++ 11)进行操作:

Suppose I have a function that does something on an arbitrary container type (C++11):

template<class containerType>
void bar( containerType& vec ) {

        for (auto i: vec) {
                std::cout << i << ", ";
        }

        std::cout << '\n';
}

我可以从另一个这样的函数调用这个函数:

I can call this function from another function like this:

void foo() {
        std::vector<int> vec = { 1, 2, 3 };
        bar(vec);
}

现在假设我像bar一样具有不同的功能，并且我想将其中一个功能传递给foo，那么foo看起来像这样:

Now suppose I have different functions just like bar, and I want to pass one of these functions to foo, then foo would look something like this:

template<class funcType>
void foo( funcType func ) {
    std::vector<int> vec = { 1, 2, 3 };
    func(vec);
}

但是，这样调用foo:

However, calling foo like this:

foo(bar);

不起作用(非常清楚，因为bar不是函数而是函数模板).有什么好的解决方案吗?我该如何定义foo才能使它正常工作?

does not work (pretty clear, since bar is not a function but a function template). Is there any nice solution to this? How must I define foo to make this work?

这是一个最小的可编译示例，根据注释的要求...

here is a minimal compileable example, as demanded in the comments...

#include <iostream>
#include <vector>
#include <list>

template<class containerType>
void bar( containerType& vec ) {

        for (auto i: vec) {
                std::cout << i << ", ";
        }

        std::cout << '\n';
}

template<typename funcType>
void foo(funcType func) {

        std::vector<int> vals = { 1, 2, 3 };
        func(vals);

}

int main() {
        // foo( bar );  - does not work.
}

推荐答案

是这样的吗? (尚未完全清醒，可能会遗漏要点)

Something like this? (not fully awake, might miss the point)

#include <iostream>
#include <vector>
#include <list>

struct Test{
template<class containerType>
static void apply( containerType& vec ) {

        for (auto it = vec.begin(); it != vec.end(); ++it) {
                std::cout << *it << ", ";
        }

        std::cout << '\n';
}
};

template<class FuncStruct>
void foo() {

        std::vector<int> vals;
        vals.push_back(1);
        FuncStruct::apply(vals);

}

int _tmain(int argc, _TCHAR* argv[])
{
    foo<Test>();
    return 0;
}

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