Creating a C++ function that calls other Lua function

问题

I wonder if it's possible to create a C++ function that takes Lua function as argument to call it.

For example in Lua,

function sub()
  print('I am sub function')
end

function main()
  callfunc(sub) //C++ function that takes a function variable to call 
end

Is it possible to create callfunc() function in C++?

I'm using SWIG by the way.

回答1:

You can create a callback by passing the Lua interpreter state down to the C++ function using the special lua_fnptr.i header. The header file also contains further usage information.

%module callback

%include <lua_fnptr.i>

%{
void callfunc(SWIGLUA_FN fn) {
    SWIGLUA_FN_GET(fn);
    lua_call(fn.L,0,0);
}
%}

void callfunc(SWIGLUA_FN fn);

local cb = require("callback")
function hello()
    print("Hello World!")
end
cb.callfunc(hello)

$ lua5.2 test.lua
Hello World!

来源：https://stackoverflow.com/questions/51145432/creating-a-c-function-that-calls-other-lua-function