Re: tostring

I think self is a cocoa keyword. Try to use " this" instead

Sent from my iPhone

On Jul 8, 2010, at 12:59, Ken Smith <[email protected]> wrote:

> I'm having a problem mapping an operator<< to tostring for my class.
> My environment is GCC 4.0 on Mac OS X 10.4+.  Here is the code.
> 
> 1 #include <iostream>
> 2
> 3 #include "lua.hpp"
> 4 #include "luabind/luabind.hpp"
> 5
> 6 struct test_t
> 7 {
> 8     test_t(const std::string& name)
> 9         :
> 10             name_(name)
> 11     {
> 12     }
> 13     friend std::ostream& operator<<(
> 14         std::ostream& os, const test_t& test
> 15     );
> 16
> 17 private:
> 18     std::string name_;
> 19 };
> 20
> 21 std::ostream& operator<<(std::ostream& os, const test_t& test)
> 22 {
> 23     os
> 24         << "test_t: "
> 25         << test.name_;
> 26
> 27     return os;
> 28 }
> 29
> 30 int main()
> 31 {
> 32     lua_State* L = luaL_newstate();
> 33     luaL_openlibs(L);
> 34     using namespace luabind;
> 35     open(L);
> 36     module(L)
> 37     [
> 38         class_<test_t>("test_t")
> 39             .def(constructor<const std::string&>())
> 40             .def(tostring(self))
> 41     ];
> 42     if (luaL_dostring(L, "t = test_t('hi') print(t)") == 1)
> 43     {
> 44         std::cout
> 45             << "Couldn't run Lua program: "
> 46             << lua_tostring(L, -1)
> 47             << std::endl;
> 48     }
> 49
> 50 }
> 
> Compiling this yields the following error.
> 
> src/main.cpp:40: error: 'self' was not declared in this scope
> src/main.cpp:40: error: 'tostring' was not declared in this scope
> 
> Commenting out line 40 causes the sample to compile but of course, the
> call to print(t) fails with:
> 
> Couldn't run Lua program: No such operator defined
> 
> How should I change this example to map test_t's operator<< to its
> __tostring metamethod in Lua?
> 
>  Regards,
>  Ken
> 
> ps. Apologies if you receive two copies of this mail.  I was not
> subscribed to the list when I sent it the first time.
> 
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