我是C 11 lambdas的新手,想通过绑定第二个参数将二元lambda变成一元lambda：
auto lambda1 = [] (int a,int b) { return a+b; };
auto lambda2 = std::bind2nd(lambda1,5);
编译失败
error: no type named 'first_argument_type' in 'struct main(int,char**)::<lambda(int,int)>'
class binder2nd
[如何才能做到这一点？
解决方法
#include <functional>
int main(int argc,char *argv[])
{
auto lambda1 = [](int a,int b) { return a+b; };
auto lambda2 = std::bind(lambda1,std::placeholders::_1,5);
// ~~~~~~~^^^^~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^~~~
return 0;
}
也更喜欢在std :: bind1st和std :: bind2nd since both were deprecated in C++11上使用std :: bind,并计划在C 17中删除.
