h1-mod/deps/sol2/examples/source/functions.cpp
2024-03-07 00:54:32 -05:00

83 lines
1.8 KiB
C++

#define SOL_ALL_SAFETIES_ON 1
#include <sol/sol.hpp>
#include <iostream>
inline int my_add(int x, int y) {
return x + y;
}
struct multiplier {
int operator()(int x) {
return x * 10;
}
static int by_five(int x) {
return x * 5;
}
};
int main() {
std::cout << "=== functions ===" << std::endl;
sol::state lua;
lua.open_libraries(sol::lib::base);
// setting a function is simple
lua.set_function("my_add", my_add);
// you could even use a lambda
lua.set_function(
"my_mul", [](double x, double y) { return x * y; });
// member function pointers and functors as well
lua.set_function("mult_by_ten", multiplier {});
lua.set_function("mult_by_five", &multiplier::by_five);
// assert that the functions work
lua.script("assert(my_add(10, 11) == 21)");
lua.script("assert(my_mul(4.5, 10) == 45)");
lua.script("assert(mult_by_ten(50) == 500)");
lua.script("assert(mult_by_five(10) == 50)");
// using lambdas, functions can have state.
int x = 0;
lua.set_function("inc", [&x]() { x += 10; });
// calling a stateful lambda modifies the value
lua.script("inc()");
SOL_ASSERT(x == 10);
if (x == 10) {
// Do something based on this information
std::cout << "Yahoo! x is " << x << std::endl;
}
// this can be done as many times as you want
lua.script(R"(
inc()
inc()
inc()
)");
SOL_ASSERT(x == 40);
if (x == 40) {
// Do something based on this information
std::cout << "Yahoo! x is " << x << std::endl;
}
// retrieval of a function is done similarly
// to other variables, using sol::function
sol::function add = lua["my_add"];
int value = add(10, 11);
// second way to call the function
int value2 = add.call<int>(10, 11);
SOL_ASSERT(value == 21);
SOL_ASSERT(value2 == 21);
if (value == 21 && value2 == 21) {
std::cout << "Woo, value is 21!" << std::endl;
}
std::cout << std::endl;
return 0;
}