set_function or new_userdata error on Windows/Code::Blocks (newbie question)

[blackmetal]

Hi, I'm totally new to sol, so maybe my compiling error is stupid. I'm working on Windows 64 bits (compiling in 32 bits) with Code::Blocks 13.12. I recompiled lua 5.2.3 like 10 minutes ago.

This simple code won't compile:

#include <sol.hpp>
#include <cassert>

struct vars {
    int boop = 0;
};

int main() {
    sol::state lua;
    lua.new_userdata<vars>("vars", "boop", &vars::boop);
    lua.script("local beep = vars.new()\n"
               "beep.boop = 1");
    assert(lua.get<vars>("beep").boop == 1);
}

When i use a simple examples (basic.cpp or variables.cpp), the code compile and works as expected but when i use the set_function or new_userdata functions like in the code above, i get the following error:

||=== Build: Debug in lua-test (compiler: GNU GCC Compiler) ===|
C:\...\sol-master\sol\traits.hpp||In instantiation of 'struct sol::detail::check_deducible_signature<void (vars::*)()>':|
...\sol-master\sol\traits.hpp|159|required from 'struct sol::has_deducible_signature<void (vars::*)()>'|
...\sol-master\sol\traits.hpp|239|required from 'struct sol::function_traits<void (vars::*)()>'|
...\sol-master\sol\traits.hpp|252|required from 'struct sol::detail::member_traits<void (vars::*)(), false>'|
...\sol-master\sol\function_types.hpp|37|required from 'struct sol::detail::functor<vars, void (vars::*)(), void>'|
...\sol-master\sol\function_types.hpp|377|required from 'struct sol::userdata_function_core<void (vars::*)(), vars>'|
...\sol-master\sol\function_types.hpp|500|required from 'struct sol::userdata_indexing_function<void (vars::*)(), vars>'|
...\lua\sol-master\sol\userdata.hpp|165|required from 'void sol::userdata<T>::build_function_tables(sol::userdata<T>::function_map_t*&, sol::userdata<T>::function_map_t*&) [with unsigned int N = 0u; T = vars; sol::userdata<T>::function_map_t = std::unordered_map<std::basic_string<char>, std::pair<std::unique_ptr<sol::base_function>, bool> >]'|
...\lua\sol-master\sol\userdata.hpp|301|required from 'void sol::userdata<T>::build_function_tables(sol::userdata<T>::function_map_t*&, sol::userdata<T>::function_map_t*&, std::string, Fx&&, Args&& ...) [with unsigned int N = 0u; Fx = int vars::*; Args = {}; T = vars; sol::userdata<T>::function_map_t = std::unordered_map<std::basic_string<char>, std::pair<std::unique_ptr<sol::base_function>, bool> >; std::string = std::basic_string<char>]'|
...\sol\userdata.hpp|330|required from 'sol::userdata<T>::userdata(std::string, sol::constructors<CArgs ...>, Args&& ...) [with Args = {const char (&)[5], int vars::*}; CArgs = {sol::types<>}; T = vars; std::string = std::basic_string<char>]'|
...\sol-master\sol\state.hpp|169|required from 'sol::state& sol::state::new_userdata(const string&, sol::constructors<CArgs ...>, Args&& ...) [with Class = vars; CArgs = {sol::types<>}; Args = {const char (&)[5], int vars::*}; sol::state = sol::state; std::string = std::basic_string<char>]'|
...\sol-master\sol\state.hpp|164|required from 'sol::state& sol::state::new_userdata(const string&, Args&& ...) [with Class = vars; CTor = {}; Args = {const char (&)[5], int vars::*}; sol::state = sol::state; std::string = std::basic_string<char>]'|
...\lua-test\main.cpp|10|required from here|
...\sol-master\sol\traits.hpp|154|error: invalid use of incomplete type 'struct sol::detail::nat'|
...\sol-master\sol\traits.hpp|152|error: forward declaration of 'struct sol::detail::nat'|
...\sol-master\sol\traits.hpp||In instantiation of 'struct sol::function_traits<void (vars::*)()>':|
...\sol-master\sol\traits.hpp|252|required from 'struct sol::detail::member_traits<void (vars::*)(), false>'|
...\sol-master\sol\function_types.hpp|37|required from 'struct sol::detail::functor<vars, void (vars::*)(), void>'|
...\lua\sol-master\sol\function_types.hpp|377|required from 'struct sol::userdata_function_core<void (vars::*)(), vars>'|
...\lua\sol-master\sol\function_types.hpp|500|required from 'struct sol::userdata_indexing_function<void (vars::*)(), vars>'|
...\lua\sol-master\sol\userdata.hpp|165|required from 'void sol::userdata<T>::build_function_tables(sol::userdata<T>::function_map_t*&, sol::userdata<T>::function_map_t*&) [with unsigned int N = 0u; T = vars; sol::userdata<T>::function_map_t = std::unordered_map<std::basic_string<char>, std::pair<std::unique_ptr<sol::base_function>, bool> >]'|
...\lua\sol-master\sol\userdata.hpp|301|required from 'void sol::userdata<T>::build_function_tables(sol::userdata<T>::function_map_t*&, sol::userdata<T>::function_map_t*&, std::string, Fx&&, Args&& ...) [with unsigned int N = 0u; Fx = int vars::*; Args = {}; T = vars; sol::userdata<T>::function_map_t = std::unordered_map<std::basic_string<char>, std::pair<std::unique_ptr<sol::base_function>, bool> >; std::string = std::basic_string<char>]'|
...\lua\sol-master\sol\userdata.hpp|330|required from 'sol::userdata<T>::userdata(std::string, sol::constructors<CArgs ...>, Args&& ...) [with Args = {const char (&)[5], int vars::*}; CArgs = {sol::types<>}; T = vars; std::string = std::basic_string<char>]'|
...\lua\sol-master\sol\state.hpp|169|required from 'sol::state& sol::state::new_userdata(const string&, sol::constructors<CArgs ...>, Args&& ...) [with Class = vars; CArgs = {sol::types<>}; Args = {const char (&)[5], int vars::*}; sol::state = sol::state; std::string = std::basic_string<char>]'|
...\lua\sol-master\sol\state.hpp|164|required from 'sol::state& sol::state::new_userdata(const string&, Args&& ...) [with Class = vars; CTor = {}; Args = {const char (&)[5], int vars::*}; sol::state = sol::state; std::string = std::basic_string<char>]'|
...\lua-test\main.cpp|10|required from here|
...\sol-master\sol\traits.hpp|239|error: 'value' is not a member of 'sol::has_deducible_signature<void (vars::*)()>'|
...\sol-master\sol\function_types.hpp||In instantiation of 'struct sol::detail::functor<vars, void (vars::*)(), void>':|
...\sol-master\sol\function_types.hpp|377|required from 'struct sol::userdata_function_core<void (vars::*)(), vars>'|
...\sol-master\sol\function_types.hpp|500|required from 'struct sol::userdata_indexing_function<void (vars::*)(), vars>'|
...\sol-master\sol\userdata.hpp|165|required from 'void sol::userdata<T>::build_function_tables(sol::userdata<T>::function_map_t*&, sol::userdata<T>::function_map_t*&) [with unsigned int N = 0u; T = vars; sol::userdata<T>::function_map_t = std::unordered_map<std::basic_string<char>, std::pair<std::unique_ptr<sol::base_function>, bool> >]'|
...\sol-master\sol\userdata.hpp|301|required from 'void sol::userdata<T>::build_function_tables(sol::userdata<T>::function_map_t*&, sol::userdata<T>::function_map_t*&, std::string, Fx&&, Args&& ...) [with unsigned int N = 0u; Fx = int vars::*; Args = {}; T = vars; sol::userdata<T>::function_map_t = std::unordered_map<std::basic_string<char>, std::pair<std::unique_ptr<sol::base_function>, bool> >; std::string = std::basic_string<char>]'|
...\sol-master\sol\userdata.hpp|330|required from 'sol::userdata<T>::userdata(std::string, sol::constructors<CArgs ...>, Args&& ...) [with Args = {const char (&)[5], int vars::*}; CArgs = {sol::types<>}; T = vars; std::string = std::basic_string<char>]'|
...\sol-master\sol\state.hpp|169|required from 'sol::state& sol::state::new_userdata(const string&, sol::constructors<CArgs ...>, Args&& ...) [with Class = vars; CArgs = {sol::types<>}; Args = {const char (&)[5], int vars::*}; sol::state = sol::state; std::string = std::basic_string<char>]'|
...\sol-master\sol\state.hpp|164|required from 'sol::state& sol::state::new_userdata(const string&, Args&& ...) [with Class = vars; CTor = {}; Args = {const char (&)[5], int vars::*}; sol::state = sol::state; std::string = std::basic_string<char>]'|
...\lua-test\main.cpp|10|required from here|
...\sol-master\sol\function_types.hpp|37|error: no type named 'args_type' in 'struct sol::detail::member_traits<void (vars::*)(), false>'|
...\sol-master\sol\function_types.hpp|38|error: no type named 'return_type' in 'struct sol::detail::member_traits<void (vars::*)(), false>'|
...\sol-master\sol\function_types.hpp|59|error: no type named 'return_type' in 'struct sol::detail::member_traits<void (vars::*)(), false>'|
...\sol-master\sol\function_types.hpp||In member function 'int sol::userdata_indexing_function<Function, Tp>::fx_call(lua_State*) [with Tx = vars*; Function = void (vars::*)(); Tp = vars; lua_State = lua_State]':|
...\sol-master\sol\function_types.hpp|540|warning: control reaches end of non-void function [-Wreturn-type]|
...\sol-master\sol\function_types.hpp||In member function 'int sol::userdata_indexing_function<Function, Tp>::fx_call(lua_State*) [with Tx = vars; Function = void (vars::*)(); Tp = vars; lua_State = lua_State]':|
...\sol-master\sol\function_types.hpp|540|warning: control reaches end of non-void function [-Wreturn-type]|
||=== Build failed: 6 error(s), 35 warning(s) (0 minute(s), 0 second(s)) ===|

Can someone tell me what i did wrong? Thanks a lot in advance :)

[Rapptz]

Thanks for the report. Unfortunately I can't reproduce.

What compiler version are you using?

[ThePhD]

Just a guess, but CodeBlocks recommends GCC 4.7.1 with its default CodeBlocks 13.12 installer.

If that's the case, you might need to explicitly pass the -std=c++11 to CodeBlock's compiler settings to make sure it's properly able to handle some of the later features.

I would also recommend downloading and using the codeblocks-13.12mingw-setup-TDM-GCC-481.exe version, since GCC 4.8.1 is the latest and greatest and starting out on an older version doesn't help you at all.

[blackmetal]

I'm currently using the gcc 4.7.1 version. In CodeBlocks, you can add this flag directly in the options (and i added it that way), i'll try to add it manually. I'll try to install a newer version of gcc and see how it goes with it. Thanks for the replies.

[blackmetal]

Ok, so now i'm in gcc 4.8.1 version, i get a segfault when i run the same script i posted above (it compiles, first victory!) The segfault is on that line:

assert(lua.get<vars>("beep").boop = 1);

It's not the assert that makes the error (i tried to remove the assert and stored the lua.get("beep") in a variable. When i tried to print &my_var the program crashed.)

[Rapptz]

Okay. Now I can reproduce. Apparently, I forgot I was building with 'Release' last time. The build is definitely failing on my end.

[Rapptz]

This is also a possible duplicate of #25 and #35 which have their own test case and pass them just fine.

[ThePhD]

Turns out this is a clerical error: the front page/examples should be fixed and this should be registered as not-a-bug.

int main() {
    sol::state lua;
    lua.new_userdata<vars>("vars", "boop", &vars::boop);
    lua.script("local beep = vars.new()\n"
               "beep.boop = 1");
    assert(lua.get<vars>("beep").boop == 1);
}

Notice in the snippet that there is local beep = ..., then the rest of the code.

local means that variable is inaccessible outside of its scope. It's not stored in the global lua table once the script is done running: it's made inaccessible and marked for garbage collection.

So it's actually behaving as it should be. Remove the local and it'll do what you want.

[ Extra Nitpicky Notes ] As a final warning, make sure you get the value with auto& if you care about not making a copy, as auto just resolves to vars and if you do vars my_vars = lua.get<vars>("beep");, whatever you have will be a copy from lua, not a reference to the actual data.

[blackmetal]

Ok :) Thanks for the answer.