chore: setup Singleton project

.envrc

@@ -0,0 +1,9 @@
+use flake .nix
+dotenv_if_exists
+
+if on_git_branch; then
+    echo 
+    git status --short --branch 
+    echo 
+    git fetch
+fi

.nix/flake.lock

@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1710222005,
+        "narHash": "sha256-irXySffHz7b82dZIme6peyAu+8tTJr1zyxcfUPhqUrg=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "9a9a7552431c4f1a3b2eee9398641babf7c30d0e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

.nix/flake.nix

@@ -0,0 +1,24 @@
+{
+  description = "A basic flake with a shell";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        devShell = pkgs.mkShell {
+          nativeBuildInputs = [ pkgs.bashInteractive ];
+          buildInputs = with pkgs; [
+            # building
+            gcc
+            cmake
+            ninja
+            sccache
+          ];
+        };
+      }
+    );
+}

Singleton/CMakeLists.txt

@@ -0,0 +1,21 @@
+cmake_minimum_required(VERSION 3.20)
+
+project(
+  Singleton
+  VERSION 0.1.0
+  LANGUAGES CXX)
+
+list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/../cmake")
+
+include(ExportCompileCommands)
+include(sccache)
+
+add_executable(Singleton main.cpp)
+
+target_compile_features(Singleton PUBLIC cxx_std_20)
+
+set_target_properties(
+  Singleton
+  PROPERTIES ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_SOURCE_DIR}/bin"
+             RUNTIME_OUTPUT_DIRECTORY "${PROJECT_SOURCE_DIR}/bin"
+             RUNTIME_OUTPUT_DIRECTORY "${PROJECT_SOURCE_DIR}/bin")

Singleton/bootstrap.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env sh
+
+cmake -S . -B .build -G Ninja -D CMAKE_EXPORT_COMPILE_COMMANDS=ON
+ln -s .build/compile_commands.json

Singleton/build.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env sh 
+
+cmake --build .build 

Singleton/main.cpp

@@ -0,0 +1,9 @@
+#include <cstdlib>
+#include <iostream>
+
+int main(int argc, char *argv[]) {
+
+  std::cout << "Singleton" << std::endl;
+
+  return EXIT_SUCCESS;
+}

cmake/ExportCompileCommands.cmake

@@ -0,0 +1,8 @@
+set(CMAKE_EXPORT_COMPILE_COMMANDS
+    ON
+    CACHE BOOL "Export compile commands database")
+
+if(CMAKE_EXPORT_COMPILE_COMMANDS)
+  set(CMAKE_CXX_STANDARD_INCLUDE_DIRECTORIES
+      ${CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES})
+endif()

cmake/sccache.cmake

@@ -0,0 +1,6 @@
+find_program(SCCACHE_FOUND sccache)
+
+if(SCCACHE_FOUND)
+  set(CMAKE_C_COMPILER_LAUNCHER sccache)
+  set(CMAKE_CXX_COMPILER_LAUNCHER sccache)
+endif()