c++ - 绑定(bind)到成员变量

Question

以下example from boost bind对我不起作用:

#include <boost/bind.hpp>

struct A
{
    int data;
};

int main()
{
    A a;
    boost::bind(&A::data, _1)(a) = 1;
}

error: assignment of read-only location 'boost::bind [with A1 = boost::arg<1>, M = int, T = A](&A::data, (<unnamed>::_1, boost::arg<1>())).boost::_bi::bind_t<R, F, L>::operator() [with A1 = A, R = const int&, F = boost::_mfi::dm<int, A>, L = boost::_bi::list1<boost::arg<1> >](((A&)(& a)))'

我做错了什么吗？编译器是g++ 4.4.0

Answer 1

该绑定(bind)表达式的结果类型是int(或者更确切地说是const int&)。我想你可以override the return type :

boost::bind<int&>(&A::data, _1)(a) = 1;