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//============================================================================
// Author : Sven Gothel
// Copyright : 2022 Gothel Software e.K.
// License : MIT
// Description : C++ Lesson 1.1 Memory (lifecycle)
//============================================================================
#include <cstdlib>
#include <cstdint>
#include <cstdio>
#include <cmath>
#include <cassert>
#include <string>
#include <memory>
#include <atomic>
#include <iostream>
/**
* Lesson 1.1
*
* Memory occupying object lifecycle:
* - Construction (default, copy, move)
* - Assigning (copy, move)
* - Referencing
* - Destruction.
*/
class sint_t; // forward
std::ostream& operator<<(std::ostream& out, const sint_t& v);
class sint_t {
private:
static std::atomic_int last_id;
int id;
int64_t store;
public:
/** Default constructor (ctor) */
sint_t() noexcept
: id(++last_id), store(0) {
std::cout << "ctor.norm: " << *this << std::endl;
}
/** Copy ctor */
sint_t(const sint_t& o) noexcept
: id(++last_id), store(o.store) {
std::cout << "ctor.copy: " << o << " -> " << *this << std::endl;
}
/** Move ctor */
sint_t(sint_t&& o) noexcept
: id( o.id ), store( o.store ) {
std::cout << "ctor.move: " << o << " -> " << *this << ", old ";
o.id = 0;
std::cout << o << std::endl;
}
/** Destructor (dtor) */
~sint_t() noexcept {
std::cout << "ctor.dtor: " << *this << std::endl;
id = 0;
}
/** Explicit conversion ctor: int64_t -> my_int_t */
explicit sint_t(const int64_t& o) noexcept
: id(++last_id), store( o ) {
std::cout << "ctor.conv: " << std::to_string( o ) << " -> " << *this << std::endl;
}
//
// Assignment operations, including arithmetic assignments
//
/** Assignment */
sint_t& operator=(const sint_t& r) noexcept {
if( this != &r ) {
store = r.store;
std::cout << "assign.copy: " << r << " -> " << *this << std::endl;
} else {
std::cout << "assign.self: " << *this << std::endl;
}
return *this;
}
/** Move-Assignment */
sint_t& operator=(sint_t&& r) noexcept {
if( this != &r ) {
std::cout << "assign.move: " << r << " -> ";
id = r.id;
store = r.store;
r.id = 0;
std::cout << *this << ", old " << r << std::endl;
} else {
std::cout << "assign.self: " << *this << std::endl;
}
return *this;
}
//
// Misc operations
//
sint_t& set(int64_t v) noexcept { store = v; return *this; }
int64_t get() const noexcept { return store; }
std::string to_string() const noexcept { return "[id "+std::to_string(id)+", val "+std::to_string(store)+"]"; }
};
std::atomic_int sint_t::last_id(0);
inline std::ostream& operator<<(std::ostream& out, const sint_t& v) {
return out << v.to_string();
}
sint_t make_obj(int64_t v) { return sint_t(v); }
const sint_t& filter10(const sint_t& o) { return o; }
sint_t filter11(const sint_t& o) { return o; }
sint_t& filter20(sint_t& o) { o.set(o.get()+1); return o; }
sint_t filter21(sint_t& o) { o.set(o.get()+1); return o; }
int main(int, const char* []) {
std::cout << "Block 1" << std::endl;
{
sint_t a;
sint_t c(a);
sint_t d = a;
(void)a; (void)c; (void)d;
// ctor.norm: [id 1, val 0]
// ctor.copy: [id 1, val 0] -> [id 2, val 0]
// ctor.copy: [id 1, val 0] -> [id 3, val 0]
// ctor.dtor: [id 3, val 0]
// ctor.dtor: [id 2, val 0]
// ctor.dtor: [id 1, val 0]
}
std::cout << "Block 2" << std::endl;
{
const sint_t& a = make_obj(1);
std::cout << "b2.a: " << a << std::endl;
const sint_t& b = filter10(a);
std::cout << "b2.b: " << b << std::endl;
(void)a; (void)b;
// ctor.conv: 1 -> [id 4, val 1]
// b2.a: [id 4, val 1]
// b2.b: [id 4, val 1]
// ctor.dtor: [id 4, val 1]
}
std::cout << "Block 3" << std::endl;
{
sint_t a = make_obj(1);
std::cout << "b3.a: " << a << std::endl;
sint_t b = make_obj(2) ;
std::cout << "b3.b: " << b << std::endl;
// ctor.conv: 1 -> [id 5, val 1]
// b3.a: [id 5, val 1]
// ctor.conv: 2 -> [id 6, val 2]
// ctor.move: [id 6, val 2] -> [id 6, val 2], old [id 0, val 2]
// ctor.dtor: [id 0, val 2]
}
std::cout << "Block 4" << std::endl;
{
sint_t a, b(2);
std::cout << "b4.0.a: " << a << std::endl;
std::cout << "b4.0.b: " << b << std::endl;
a = std::move( b ); // b should not be dereferenced after move
std::cout << "b4.1.a: " << a << std::endl;
a = make_obj(3) ;
std::cout << "b4.2.a: " << a << std::endl;
// ctor.norm: [id 7, val 0]
// ctor.conv: 2 -> [id 8, val 2]
// b4.0.a: [id 7, val 0]
// b4.0.b: [id 8, val 2]
// assign.move: [id 8, val 2] -> [id 8, val 2], old [id 0, val 2]
// b4.1.a: [id 8, val 2]
// ctor.conv: 3 -> [id 9, val 3]
// assign.move: [id 9, val 3] -> [id 9, val 3], old [id 0, val 3]
// ctor.dtor: [id 0, val 3]
// b4.2.a: [id 9, val 3]
// ctor.dtor: [id 0, val 2]
// ctor.dtor: [id 9, val 3]
}
return 0;
}
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