bind 简单用法

bind_test.cpp

#include <fmt/format.h>
#include <console_color.h>
#include <boost/bind.hpp>

using namespace std;
using namespace fmt;
using namespace concol;
using namespace boost;

int f(int a, int b) { return a + b; }
int g(int a, int b, int c) { return a + b * c; }
typedef int(*f_type)(int, int);
typedef int(*g_type)(int, int, int);

class Demo {
public:
    int f(int a, int b) { return a + b; }
};

int main(int argc, char **argv)
{
    init();
    // common bind
    cout << bind(f, 1, 2)() << endl;
    auto g1 = bind(g, 1, 2, 3);
    cout << g1() << endl;
    print_cyan_line();

    // postitional bind
    cout << bind(f, _1, 9)(3) << endl; // 12
    cout << bind(f, _1, _2)(4, 6) << endl; // 10
    cout << bind(f, _1, _1)(9, 10) << endl; // 18
    print_cyan_line();

    // bind function pointer
    f_type pf = f;
    g_type pg = g;
    cout << bind(pf, _1, 8)(7) << endl; // 15
    cout << bind(pg, _3, _2, _1)(2, 3, 4) << endl; //10
    print_cyan_line();

    // bind member function by instance, reference and class pointer
    Demo a, &ra = a;
    Demo* p = &a;
    cout << bind(&Demo::f, a, _1, 20)(10) << endl;
    cout << bind(&Demo::f, ra, _1, 20)(11) << endl;
    cout << bind(&Demo::f, p, _1, 20)(12) << endl;
    print_cyan_line();

    cout << "Press any key to exit..." << endl;
    get_char();
    return 0;
}

运行结果