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#define SOL_ALL_SAFETIES_ON 1
#include <sol/sol.hpp>
#include <iostream>
int main(int, char*[]) {
std::cout << "=== functions empty args ===" << std::endl;
// sol::reference, sol::Stack_reference,
// sol::object (and main_* types) can all be
// used to capture "nil", or "none" when a function
// leaves it off
auto my_defaulting_function
= [](sol::object maybe_defaulted) -> int {
// if it's nil, it's "unused" or "inactive"
bool inactive = maybe_defaulted == sol::lua_nil;
if (inactive) {
return 0;
}
if (maybe_defaulted.is<int>()) {
int value = maybe_defaulted.as<int>();
return value;
}
return 1;
};
sol::state lua;
lua.open_libraries(sol::lib::base);
// copy function in (use std::ref to change this behavior)
lua.set_function(
"defaulting_function", my_defaulting_function);
sol::string_view code = R"(
result = defaulting_function(24)
result_nothing = defaulting_function()
result_nil = defaulting_function(nil)
result_string = defaulting_function('meow')
print('defaulting_function(24), returned:', result)
print('defaulting_function(), returned:', result_nothing)
print('defaulting_function(nil), returned:', result_nil)
print('defaulting_function(\'meow\'), returned:', result_string)
assert(result == 24)
assert(result_nothing == 0)
assert(result_nil == 0)
assert(result_string == 1)
)";
lua.safe_script(code);
std::cout << std::endl;
return 0;
}
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