75 lines
1.4 KiB
C++
75 lines
1.4 KiB
C++
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#define SOL_ALL_SAFETIES_ON 1
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#include <sol/sol.hpp>
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#include <iostream>
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#include <memory>
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#include <mutex>
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struct SomeLib {
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private:
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SomeLib() {
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}
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public:
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static std::shared_ptr<SomeLib> getInstance();
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int doSomething() const {
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return 20;
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}
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// destructor must be public to work with
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// std::shared_ptr and friends
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// if you need it to be private, you must implement
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// a custom deleter with access to the private members
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// (e.g., a deleter struct defined in this class)
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~SomeLib() {
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}
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};
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std::shared_ptr<SomeLib> SomeLib::getInstance() {
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static std::weak_ptr<SomeLib> instance;
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static std::mutex m;
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m.lock();
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auto ret = instance.lock();
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if (!ret) {
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ret.reset(new SomeLib());
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instance = ret;
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}
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m.unlock();
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return ret;
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}
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int main(int, char*[]) {
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std::cout << "=== singleton ===" << std::endl;
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sol::state lua;
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lua.open_libraries(sol::lib::base);
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lua.new_usertype<SomeLib>("SomeLib",
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"new",
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sol::no_constructor,
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"getInstance",
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&SomeLib::getInstance,
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"doSomething",
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&SomeLib::doSomething);
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lua.script(R"(
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-- note we use the `.` here, not `:` (there's no self to access)
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local sli = SomeLib.getInstance()
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-- we use the `:` here because there is something to access
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local value = sli:doSomething()
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-- check
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print('sli:doSomething() returned:', value)
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assert(value == 20)
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)");
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std::cout << std::endl;
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return 0;
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}
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