错误:重载的“bind(int(Class::*)(int,int),Class*,int,int”的调用不明确

error: call of overloaded ‘bind(int (Class::*)(int, int), Class*, int, int)’ is ambiguous

本文关键字:int Class 不明确 调用 错误 重载 bind      更新时间:2023-10-16

我正在尝试使用boost::bind,有人能告诉我下面的代码段哪里错了吗?

#include <iostream>
#include <boost/bind.hpp>
using std::cout;
using std::endl;
class Class {
public:
    int add(int x, int y) {
        cout << "x+y=" <<x+y<<endl;
        return x+y;
    }
};
int main()
{
    cout << "boost::thread: " << endl;
    Class cls;
    boost::bind<int>(&Class::add, &cls, 1, 2);
    return 0;
}

在我的编译器g++-4.7中,它说:

main.cpp: In function ‘int main()’:
main.cpp:26:45: error: call of overloaded ‘bind(int (Class::*)(int, int), Class*, int, int)’ is ambiguous
     boost::bind<int>(&Class::add, &cls, 1, 2);
                                             ^
main.cpp:26:45: note: candidates are:
In file included from /usr/include/boost/bind.hpp:22:0,
                 from main.cpp:3:
/usr/include/boost/bind/bind.hpp:1610:5: note: boost::_bi::bind_t<R, F, typename boost::_bi::list_av_3<A1, A2, A3>::type> boost::bind(F, A1, A2, A3) [with R = int; F = int (Class::*)(int, int); A1 = Class*; A2 = int; A3 = int; typename boost::_bi::list_av_3<A1, A2, A3>::type = boost::_bi::list3<boost::_bi::value<Class*>, boost::_bi::value<int>, boost::_bi::value<int> >]
     BOOST_BIND(F f, A1 a1, A2 a2, A3 a3)
     ^
/usr/include/boost/bind/bind_mf_cc.hpp:109:5: note: boost::_bi::bind_t<R, boost::_mfi::mf2<R, T, A1, A2>, typename boost::_bi::list_av_3<A1, A2, A3>::type> boost::bind(R (T::*)(B1, B2), A1, A2, A3) [with R = int; T = Class; B1 = int; B2 = int; A1 = Class*; A2 = int; A3 = int; typename boost::_bi::list_av_3<A1, A2, A3>::type = boost::_bi::list3<boost::_bi::value<Class*>, boost::_bi::value<int>, boost::_bi::value<int> >]
     BOOST_BIND(R (BOOST_BIND_MF_CC T::*f) (B1, B2), A1 a1, A2 a2, A3 a3)
     ^
/usr/include/boost/bind/bind_mf_cc.hpp:131:5: note: boost::_bi::bind_t<Rt2, boost::_mfi::mf2<R, T, B1, B2>, typename boost::_bi::list_av_3<A1, A2, A3>::type> boost::bind(R (T::*)(B1, B2), A1, A2, A3) [with Rt2 = int; R = int; T = Class; B1 = int; B2 = int; A1 = Class*; A2 = int; A3 = int; typename boost::_bi::list_av_3<A1, A2, A3>::type = boost::_bi::list3<boost::_bi::value<Class*>, boost::_bi::value<int>, boost::_bi::value<int> >]
     BOOST_BIND(R (BOOST_BIND_MF_CC T::*f) (B1, B2), A1 a1, A2 a2, A3 a3)

我知道这是一个过载问题,但头文件是自动包含的,下一步该怎么办?

简单,更改此行:

boost::bind<int>(&Class::add, &cls, 1, 2);

boost::bind(&Class::add, &cls, 1, 2)();

bind返回一个函数,您需要使用operator()来调用它。

顺便说一句,您在C++11中不需要boost::bind。包括<functional>并使用std::bind

尝试在对boost::bind的调用中去掉<int>。你使用的是什么版本的boost?boost版本1.58有一个错误,可能会导致这种歧义:https://svn.boost.org/trac/boost/ticket/11304