如何在 VC 中将 lambda 函数与 boost::bind/std::bind 一起使用2010年？

发布于 2024-10-10 13:47:54 字数 615 浏览 0 评论 0原文

我有一些 lambda 函数，我想使用 boost::bind 或 std::bind 进行绑定。（不在乎哪一个，只要它有效即可。）不幸的是，它们都给了我不同的编译器错误：

auto f = [](){ cout<<"f()"<<endl; };
auto f2 = [](int x){ cout<<"f2() x="<<x<<endl; };

std::bind(f)(); //ok
std::bind(f2, 13)(); //error C2903: 'result' : symbol is neither a class template nor a function template

boost::bind(f)(); //error C2039: 'result_type' : is not a member of '`anonymous-namespace'::<lambda0>'
boost::bind(f2, 13)(); //error C2039: 'result_type' : is not a member of '`anonymous-namespace'::<lambda1>'

那么，最简单的解决方法是什么？

原文

I have some lambda functions which I want to bind using either boost::bind or std::bind. (Don't care which one, as long as it works.) Unfortunately both of them give me different compiler erros:

auto f = [](){ cout<<"f()"<<endl; };
auto f2 = [](int x){ cout<<"f2() x="<<x<<endl; };

std::bind(f)(); //ok
std::bind(f2, 13)(); //error C2903: 'result' : symbol is neither a class template nor a function template

boost::bind(f)(); //error C2039: 'result_type' : is not a member of '`anonymous-namespace'::<lambda0>'
boost::bind(f2, 13)(); //error C2039: 'result_type' : is not a member of '`anonymous-namespace'::<lambda1>'

So, what is the simplest workaround for this?

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影子是时光的心 2024-10-17 13:47:54

您需要手动指定返回类型：

boost::bind<void>(f)();
boost::bind<int>(f2, 13)();

如果您不喜欢显式告诉bind，您还可以自己编写一个模板函数，使用Boost.FunctionTypes 自动推导返回类型来检查您的lambda 的operator()。

You need to manually specify the return type:

boost::bind<void>(f)();
boost::bind<int>(f2, 13)();

You can also write yourself a template-function to deduce the return type automagically using Boost.FunctionTypes to inspect your lambda's operator(), if you don't like to explicitly tell bind.

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美煞众生 2024-10-17 13:47:54

std::function<void ()> f1 = [](){ std::cout<<"f1()"<<std::endl; };
std::function<void (int)> f2 = [](int x){ std::cout<<"f2() x="<<x<<std::endl; };
boost::function<void ()> f3 = [](){ std::cout<<"f3()"<<std::endl; };
boost::function<void (int)> f4 = [](int x){ std::cout<<"f4() x="<<x<<std::endl; };

//do you still wanna bind?
std::bind(f1)(); //ok
std::bind(f2, 13)(); //ok
std::bind(f3)(); //ok
std::bind(f4, 13)(); //ok

//do you still wanna bind?
boost::bind(f1)(); //ok
boost::bind(f2, 13)(); //ok
boost::bind(f3)(); //ok
boost::bind(f4, 13)(); //ok

std::function<void ()> f1 = [](){ std::cout<<"f1()"<<std::endl; };
std::function<void (int)> f2 = [](int x){ std::cout<<"f2() x="<<x<<std::endl; };
boost::function<void ()> f3 = [](){ std::cout<<"f3()"<<std::endl; };
boost::function<void (int)> f4 = [](int x){ std::cout<<"f4() x="<<x<<std::endl; };

//do you still wanna bind?
std::bind(f1)(); //ok
std::bind(f2, 13)(); //ok
std::bind(f3)(); //ok
std::bind(f4, 13)(); //ok

//do you still wanna bind?
boost::bind(f1)(); //ok
boost::bind(f2, 13)(); //ok
boost::bind(f3)(); //ok
boost::bind(f4, 13)(); //ok

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