Restructing the source layout to make it nicer.

Makefile

@@ -1,7 +1,7 @@
 all: build test
 
 patch:
-	cp .\patches\process.h .\subprojects\libgit2-1.8.1\src\util\process.h
+	powershell "cp ./patches/process.h ./subprojects/libgit2-1.8.1/src/util/process.h"
 
 build:
 	meson compile -j 4 -C builddir
@@ -11,6 +11,8 @@ test:
 
 # make an install for real maybe copy dll and .exe to dir and zip?
 install: build test
+	powershell "cp ./builddir/subprojects/libgit2-1.8.1/liblibgit2package.dll ."
+	powershell "cp ./builddir/subprojects/efsw/libefsw.dll ."
 	powershell "cp builddir/escape_turings_tarpit.exe ."
 
 run: install

meson.build

@@ -25,6 +25,8 @@ dependencies = [
   sfml, imgui, json
 ]
 
+subdir('scratchpad')
+
 executable('escape_turings_tarpit',
   ['game_engine.cpp',
     'gui.cpp',
@@ -34,30 +36,6 @@ executable('escape_turings_tarpit',
     'escape_turings_tarpit.cpp'],
   dependencies: dependencies)
 
-executable('regtest', 'regtest.cpp',
-  dependencies: [fmt])
-
-executable('audiotest', 'audiotest.cpp',
-  dependencies: dependencies)
-
-executable('jsontest', 'jsontest.cpp',
-  dependencies: dependencies)
-
-executable('threadtest', 'threadtest.cpp',
-  dependencies: dependencies)
-
-executable('fsmtest', 'fsmtest.cpp',
-  dependencies: dependencies)
-
-executable('badref', 'badref.cpp',
-  dependencies: dependencies)
-
-executable('corotest', [
-    'corotest.cpp'
-  ],
-  dependencies: dependencies,
-  cpp_args: '-fcoroutines')
-
 runtests = executable('runtests', [
   'game_engine.cpp',
   'tests/game_engine.cpp',

scratchpad/corotest.cpp

@@ -1,4 +1,4 @@
-#include "coro.hpp"
+#include "../coro.hpp"
 #include <coroutine>
 #include <vector>
 #include <iostream>

scratchpad/fsmtest.cpp

@@ -1,5 +1,5 @@
 #include <fmt/core.h>
-#include "fsm.hpp"
+#include "../fsm.hpp"
 
 using namespace fmt;
 

scratchpad/ftx_thread_test.cpp

@@ -9,9 +9,9 @@
 #include <string>                  // for operator+, to_string
 #include <thread>                  // for sleep_for
 
-#include "ftxui/component/component.hpp"  // for CatchEvent, Renderer, operator|=
-#include "ftxui/component/loop.hpp"       // for Loop
-#include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
+#include <ftxui/component/component.hpp>  // for CatchEvent, Renderer, operator|=
+#include <ftxui/component/loop.hpp>       // for Loop
+#include <ftxui/component/screen_interactive.hpp>  // for ScreenInteractive
 
 using namespace ftxui;
 

scratchpad/ftxtest.cpp

@@ -8,9 +8,9 @@
 #include <string>                  // for operator+, to_string
 #include <thread>                  // for sleep_for
 
-#include "ftxui/component/component.hpp"  // for CatchEvent, Renderer, operator|=
-#include "ftxui/component/loop.hpp"       // for Loop
-#include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
+#include <ftxui/component/component.hpp>  // for CatchEvent, Renderer, operator|=
+#include <ftxui/component/loop.hpp>       // for Loop
+#include <ftxui/component/screen_interactive.hpp>  // for ScreenInteractive
 #include <vector>
 
 using namespace ftxui;

scratchpad/meson.build

@@ -0,0 +1,23 @@
+executable('regtest', 'regtest.cpp',
+  dependencies: [fmt])
+
+executable('audiotest', 'audiotest.cpp',
+  dependencies: dependencies)
+
+executable('jsontest', 'jsontest.cpp',
+  dependencies: dependencies)
+
+executable('threadtest', 'threadtest.cpp',
+  dependencies: dependencies)
+
+executable('fsmtest', 'fsmtest.cpp',
+  dependencies: dependencies)
+
+executable('badref', 'badref.cpp',
+  dependencies: dependencies)
+
+executable('corotest', [
+    'corotest.cpp'
+  ],
+  dependencies: dependencies,
+  cpp_args: '-fcoroutines')

scratchpad/uniqptrtest.cpp

@@ -0,0 +1,130 @@
+#include <cassert>
+#include <cstdio>
+#include <fstream>
+#include <iostream>
+#include <locale>
+#include <memory>
+#include <stdexcept>
+
+// helper class for runtime polymorphism demo below
+struct B
+{
+    virtual ~B() = default;
+
+    virtual void bar() { std::cout << "B::bar\n"; }
+};
+
+struct D : B
+{
+    D() { std::cout << "D::D\n"; }
+    ~D() { std::cout << "D::~D\n"; }
+
+    void bar() override { std::cout << "D::bar\n"; }
+};
+
+// a function consuming a unique_ptr can take it by value or by rvalue reference
+std::unique_ptr<D> pass_through(std::unique_ptr<D> p)
+{
+    p->bar();
+    return p;
+}
+
+// helper function for the custom deleter demo below
+void close_file(std::FILE* fp)
+{
+    std::fclose(fp);
+}
+
+// unique_ptr-based linked list demo
+struct List
+{
+    struct Node
+    {
+        int data;
+        std::unique_ptr<Node> next;
+    };
+
+    std::unique_ptr<Node> head;
+
+    ~List()
+    {
+        // destroy list nodes sequentially in a loop, the default destructor
+        // would have invoked its `next`'s destructor recursively, which would
+        // cause stack overflow for sufficiently large lists.
+        while (head)
+        {
+            auto next = std::move(head->next);
+            head = std::move(next);
+        }
+    }
+
+    void push(int data)
+    {
+        head = std::unique_ptr<Node>(new Node{data, std::move(head)});
+    }
+};
+
+int main()
+{
+    std::cout << "1) Unique ownership semantics demo\n";
+    {
+        // Create a (uniquely owned) resource
+        std::unique_ptr<D> p = std::make_unique<D>();
+
+        // Transfer ownership to `pass_through`,
+        // which in turn transfers ownership back through the return value
+        std::unique_ptr<D> q = pass_through(std::move(p));
+
+        // p is now in a moved-from 'empty' state, equal to nullptr
+        assert(!p);
+    }
+
+    std::cout << "\n" "2) Runtime polymorphism demo\n";
+    {
+        // Create a derived resource and point to it via base type
+        std::unique_ptr<B> p = std::make_unique<D>();
+
+        // Dynamic dispatch works as expected
+        p->bar();
+    }
+
+    std::cout << "\n" "3) Custom deleter demo\n";
+    std::ofstream("demo.txt") << 'x'; // prepare the file to read
+    {
+        using unique_file_t = std::unique_ptr<std::FILE, decltype(&close_file)>;
+        unique_file_t fp(std::fopen("demo.txt", "r"), &close_file);
+        if (fp)
+            std::cout << char(std::fgetc(fp.get())) << '\n';
+    } // `close_file()` called here (if `fp` is not null)
+
+    std::cout << "\n" "4) Custom lambda-expression deleter and exception safety demo\n";
+    try
+    {
+        std::unique_ptr<D, void(*)(D*)> p(new D, [](D* ptr)
+        {
+            std::cout << "destroying from a custom deleter...\n";
+            delete ptr;
+        });
+
+        throw std::runtime_error(""); // `p` would leak here if it were a plain pointer
+    }
+    catch (const std::exception&)
+    {
+        std::cout << "Caught exception\n";
+    }
+
+    std::cout << "\n" "5) Array form of unique_ptr demo\n";
+    {
+        std::unique_ptr<D[]> p(new D[3]);
+    } // `D::~D()` is called 3 times
+
+    std::cout << "\n" "6) Linked list demo\n";
+    {
+        List wall;
+        const int enough{1'000'000};
+        for (int beer = 0; beer != enough; ++beer)
+            wall.push(beer);
+
+        std::cout << enough << " bottles of beer on the wall...\n";
+    } // destroys all the beers
+}