C++闭合破解

当然,你的例子没什么用。它只能在 function .

免费C++ 0x插头:

#include <functional>

void some_function( int x ) { }

void function( int value ) {
    struct closure {
         std::function< void() > operator()( int value )
             { return [=](){ some_function( value ); }; }
    };

    auto a = closure()( value );
    auto b = closure()( 5 );

    a();
    b();
    b();
}

class Closure
{
    public:
        Closure(std::string const& g)
           :greet(g)
        {}
       void operator()(std::string const& g2)
       {
            std::cout << greet << " " << g2;
       } 
    private:
        std::string   greet;
};

int main()
{
    Closure   c("Hello");

    c("World");  // C acts like a function with state. Whooo.
}

在C++ 11中使用新的lambda语法,它变得更容易。

int main()
{
    std::string g("Hello");

    auto c = [g](std::string const& m)  {std::cout << g << " " << m;};

    c("World");
}

在C++ 14中新扩展的lambda语法(gt= C++ +1y在GCC上)变得更容易。

int main()
{
    auto c = [g="Hello"](std::string const& m)  {std::cout << g << " " << m;};

    c("World");
}