1 files changed, 82 insertions, 0 deletions
diff --git a/deps/sol2/examples/source/environments_on_functions.cpp b/deps/sol2/examples/source/environments_on_functions.cpp
new file mode 100644
index 0000000..baa0e77
--- /dev/null
+++ b/deps/sol2/examples/source/environments_on_functions.cpp
@@ -0,0 +1,82 @@
+#define SOL_ALL_SAFETIES_ON 1
+#include <sol/sol.hpp>
+
+#include "assert.hpp"
+#include <iostream>
+
+int main(int, char**) {
+	sol::state lua;
+	lua.open_libraries(sol::lib::base);
+
+	// Environments can set on functions (scripts), userdata and threads
+	// let's look at functions
+
+	lua.script("f = function() return test end");
+	sol::function f = lua["f"];
+	
+	sol::environment env_f(lua, sol::create);
+	env_f["test"] = 31;
+	sol::set_environment(env_f, f);
+
+	// the function returns the value from the environment table
+	int result = f();
+	c_assert(result == 31);
+
+	
+	// You can also protect from variables
+	// being set without the 'local' specifier
+	lua.script("g = function() test = 5 end");
+	sol::function g = lua["g"];
+	sol::environment env_g(lua, sol::create);
+	env_g.set_on(g); // same as set_environment
+
+	g();
+	// the value can be retrieved from the env table
+	int test = env_g["test"];
+	c_assert(test == 5);
+
+
+	// the global environment
+	// is not polluted at all, despite both functions being used and set
+	sol::object global_test = lua["test"];
+	c_assert(!global_test.valid());
+
+
+	// You can retrieve environments in C++
+	// and check the environment of functions
+	// gotten from Lua
+
+	// get the environment from any sol::reference-styled type,
+	// including sol::object, sol::function, sol::table, sol::userdata ...
+	lua.set_function("check_f_env",
+		// capture necessary variable in C++ lambda
+		[&env_f]( sol::object target ) {
+			// pull out the environment from func using
+			// sol::env_key constructor
+			sol::environment target_env(sol::env_key, target);
+			int test_env_f = env_f["test"];
+			int test_target_env = target_env["test"];
+			// the environment for f the one gotten from `target`
+			// are the same
+			c_assert(test_env_f == test_target_env);
+			c_assert(test_env_f == 31);
+			c_assert(env_f == target_env);
+		}
+	);
+	lua.set_function("check_g_env",
+		[&env_g](sol::function target) {
+			// equivalent:
+			sol::environment target_env = sol::get_environment(target);
+			int test_env_g = env_g["test"];
+			int test_target_env = target_env["test"];
+			c_assert(test_env_g == test_target_env);
+			c_assert(test_env_g == 5);
+			c_assert(env_g == target_env);
+		}
+	);
+
+	lua.script("check_f_env(f)");
+	lua.script("check_g_env(g)");
+
+	return 0;
+}