7 files changed, 242 insertions, 0 deletions
diff --git a/graphs/cpp/my_nfts/auction.cc b/graphs/cpp/my_nfts/auction.cc
new file mode 100644
index 0000000..534c61d
--- /dev/null
+++ b/graphs/cpp/my_nfts/auction.cc
@@ -0,0 +1,45 @@
+#include "auction.hh"
+
+#include <algorithm>
+Auction::Auction(Person& organizer, NFT nft, uint initial_bid)
+    : organizer_{ organizer }
+    , nft_{ std::move(nft) }
+    , highest_bidder_{ nullptr }
+    , highest_bid_{ initial_bid }
+{
+    if (!nft_ || nft_->empty())
+        throw std::invalid_argument{ "Invalid nft!" };
+}
+Auction::~Auction()
+{
+    if (highest_bidder_ == nullptr)
+        organizer_.add_nft(std::move(nft_));
+    else
+    {
+        highest_bidder_->add_nft(std::move(nft_));
+        organizer_.add_money(highest_bid_);
+    }
+}
+bool Auction::bid(Person& person, uint money)
+{
+    if (money > highest_bid_)
+    {
+        if (highest_bidder_ == nullptr)
+            highest_bidder_ = &person;
+        else
+            highest_bidder_->add_money(highest_bid_);
+        highest_bid_ = money;
+        highest_bidder_ = &person;
+        highest_bidder_->remove_money(money);
+        return true;
+    }
+    return false;
+}
+const std::string& Auction::get_nft_name() const
+{
+    return *nft_;
+}
+uint Auction::get_highest_bid() const
+{
+    return highest_bid_;
+}
+\ No newline at end of file
diff --git a/graphs/cpp/my_nfts/auction.hh b/graphs/cpp/my_nfts/auction.hh
new file mode 100644
index 0000000..9a1d162
--- /dev/null
+++ b/graphs/cpp/my_nfts/auction.hh
@@ -0,0 +1,34 @@
+#pragma once
+
+#include "nft.hh"
+#include "person.hh"
+
+// Smart contract to auction a NFT.
+// It is a RAII class.
+class Auction
+{
+public:
+    // Start the auction with the given (non-null) NFT.
+    Auction(Person& organizer, NFT nft, uint initial_bid);
+    // Close the auction.
+    ~Auction();
+
+    // https://en.cppreference.com/w/cpp/language/rule_of_three#Rule_of_five
+    Auction(const Auction&&) = delete;
+    Auction(const Auction&) = delete;
+    Auction& operator=(const Auction&&) = delete;
+    Auction& operator=(const Auction&) = delete;
+
+    // Allow a person to bid at the auction.
+    bool bid(Person& person, uint money);
+
+    // Getters for the nft name and highest bid.
+    const std::string& get_nft_name() const;
+    uint get_highest_bid() const;
+
+private:
+    Person& organizer_;
+    NFT nft_;
+    Person* highest_bidder_;
+    uint highest_bid_;
+};
diff --git a/graphs/cpp/my_nfts/main.cc b/graphs/cpp/my_nfts/main.cc
new file mode 100644
index 0000000..2e9f462
--- /dev/null
+++ b/graphs/cpp/my_nfts/main.cc
@@ -0,0 +1,37 @@
+#include <iostream>
+
+#include "auction.hh"
+#include "person.hh"
+
+int main(void)
+{
+    auto p1 = Person("JP", 100);
+    auto p2 = Person("Claude", 50);
+
+    p1.add_nft(create_nft("Singe"));
+
+    std::cout << p1;
+    std::cout << p2;
+
+    p2.add_nft(p1.remove_nft("Singe"));
+
+    std::cout << p1;
+    std::cout << p2;
+
+    auto p3 = Person("Marie", 20);
+    std::cout << p1;
+    std::cout << p2;
+    std::cout << p3;
+
+    {
+        Auction auction(p2, p2.remove_nft("Singe"), 10);
+        std::cout << p1;
+        std::cout << p2;
+        std::cout << p3;
+
+        auction.bid(p1, 20);
+    }
+    std::cout << p1;
+    std::cout << p2;
+    std::cout << p3;
+}
diff --git a/graphs/cpp/my_nfts/nft.hh b/graphs/cpp/my_nfts/nft.hh
new file mode 100644
index 0000000..2147545
--- /dev/null
+++ b/graphs/cpp/my_nfts/nft.hh
@@ -0,0 +1,15 @@
+#pragma once
+
+#include <memory>
+#include <string>
+
+// NFT declaration
+using NFT = std::unique_ptr<std::string>;
+
+// Create an empty NFT (convient in some scenarios).
+NFT create_empty_nft();
+// Create a NFT with the given name.
+NFT create_nft(const std::string& name);
+
+// Define the functions in the nft.hxx file.
+#include "nft.hxx"
diff --git a/graphs/cpp/my_nfts/nft.hxx b/graphs/cpp/my_nfts/nft.hxx
new file mode 100644
index 0000000..083f10f
--- /dev/null
+++ b/graphs/cpp/my_nfts/nft.hxx
@@ -0,0 +1,11 @@
+#pragma once
+
+#include "nft.hh"
+inline NFT create_empty_nft()
+{
+    return nullptr;
+}
+inline NFT create_nft(const std::string& name)
+{
+    return std::make_unique<std::string>(name);
+}
+\ No newline at end of file
diff --git a/graphs/cpp/my_nfts/person.cc b/graphs/cpp/my_nfts/person.cc
new file mode 100644
index 0000000..cf4b291
--- /dev/null
+++ b/graphs/cpp/my_nfts/person.cc
@@ -0,0 +1,61 @@
+#include "person.hh"
+
+#include <algorithm>
+Person::Person(const std::string& name, uint money)
+    : name_{ name }
+    , money_{ money }
+{}
+std::vector<std::string> Person::enumerate_nfts() const
+{
+    std::vector<std::string> res;
+    for (auto nft = nfts_.begin(); nft != nfts_.end(); nft++)
+    {
+        res.push_back(**nft);
+    }
+    return res;
+}
+void Person::add_nft(NFT nft)
+{
+    nfts_.push_back(std::move(nft));
+}
+NFT Person::remove_nft(const std::string& name)
+{
+    auto pos = std::find_if(nfts_.begin(), nfts_.end(),
+                            [&](NFT const& nft) { return *nft == name; });
+    if (pos == nfts_.end())
+        return create_empty_nft();
+    nfts_.erase(pos);
+    return create_nft(name);
+}
+void Person::add_money(uint money)
+{
+    money_ += money;
+}
+bool Person::remove_money(uint money)
+{
+    if (money > money_)
+        return false;
+    money_ -= money;
+    return true;
+}
+uint Person::get_money() const
+{
+    return money_;
+}
+const std::string& Person::get_name() const
+{
+    return name_;
+}
+std::ostream& operator<<(std::ostream& os, const Person& p)
+{
+    os << "Name: " << p.get_name() << "\nMoney: " << p.get_money() << "\nNFTs:";
+    if (const std::vector<std::string> nfts = p.enumerate_nfts(); !nfts.empty())
+    {
+        for (size_t i = 0; i < nfts.size(); ++i)
+        {
+            os << " " << nfts.at(i);
+        }
+    }
+    os << "\n";
+    return os;
+}
diff --git a/graphs/cpp/my_nfts/person.hh b/graphs/cpp/my_nfts/person.hh
new file mode 100644
index 0000000..90a2e16
--- /dev/null
+++ b/graphs/cpp/my_nfts/person.hh
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <ostream>
+#include <vector>
+
+#include "nft.hh"
+
+// A person
+class Person
+{
+public:
+    // Initiliaze its member attributes.
+    Person(const std::string& name, uint money);
+
+    // Returns the list of NFTs it owns.
+    std::vector<std::string> enumerate_nfts() const;
+
+    // Give it a NFT.
+    void add_nft(NFT nft);
+    // Take away a NFT.
+    NFT remove_nft(const std::string& name);
+
+    // Add money.
+    void add_money(uint money);
+    // Remove money, if possible.
+    bool remove_money(uint money);
+
+    // Getters for money and name.
+    uint get_money() const;
+    const std::string& get_name() const;
+
+private:
+    std::string name_;
+    uint money_;
+    std::vector<NFT> nfts_;
+};
+
+// Write informations about the person on the given stream.
+std::ostream& operator<<(std::ostream& os, const Person& p);