From 9041abce7a2d190017de0898c96d30ad965b5f57 Mon Sep 17 00:00:00 2001
From: Mike Dev <mike.dev@gmx.de>
Date: Mon, 15 Oct 2018 18:28:28 +0200
Subject: [PATCH] Let user choose which filesystem lib (std/boost) to use

---
 CMakeLists.txt   | 23 +++++++++++++++++++++--
 src/boostdep.cpp | 25 ++++++++++++++++++-------
 2 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0bc5834..c134974 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,9 +7,28 @@ cmake_minimum_required( VERSION 3.1 )
 
 project( boostdep LANGUAGES CXX )
 
+option( BOOSTDEP_USE_STD_FS "Use std::filesystem instead of boost::filesystem" OFF )
+
 add_executable( boostdep src/boostdep.cpp )
 
-find_package( Boost COMPONENTS filesystem REQUIRED )
-target_link_libraries( boostdep Boost::filesystem )
+if( BOOSTDEP_USE_STD_FS )
+
+    message(STATUS "Using std::filesystem as filesystem library")
+
+    target_compile_definitions( boostdep PUBLIC BOOSTDEP_USE_STD_FS )
+    target_compile_features( boostdep PUBLIC cxx_std_17 )
+
+    # NOTE: Some compilers (e.g. g++-8) will require additional linker flags
+    #        in order to use std::filesystem (e.g. -lstdc++fs).
+    #        We are NOT handling those special cases
+
+else()
+
+    message(STATUS "Using Boost::filesystem as filesystem library")
+
+    find_package( Boost COMPONENTS filesystem REQUIRED )
+    target_link_libraries( boostdep PUBLIC Boost::filesystem )
+
+endif()
 
 install( TARGETS boostdep RUNTIME DESTINATION bin )
diff --git a/src/boostdep.cpp b/src/boostdep.cpp
index f517d2d..27488c0 100644
--- a/src/boostdep.cpp
+++ b/src/boostdep.cpp
@@ -9,8 +9,6 @@
 
 #define _CRT_SECURE_NO_WARNINGS
 
-#include <boost/filesystem.hpp>
-#include <boost/filesystem/fstream.hpp>
 #include <string>
 #include <iostream>
 #include <fstream>
@@ -23,7 +21,16 @@
 #include <streambuf>
 #include <sstream>
 
-namespace fs = boost::filesystem;
+#ifdef BOOSTDEP_USE_STD_FS
+    #include <filesystem>
+    namespace fs = std::filesystem;
+#else
+    #include <boost/filesystem.hpp>
+    #include <boost/filesystem/fstream.hpp>
+    namespace fs = boost::filesystem;
+#endif
+
+
 
 // header -> module
 static std::map< std::string, std::string > s_header_map;
@@ -50,7 +57,7 @@ static void scan_module_headers( fs::path const & path )
 
         for( ; it != last; ++it )
         {
-            if( it->status().type() == fs::directory_file )
+            if( fs::is_directory( it->status() ) )
             {
                 continue;
             }
@@ -76,7 +83,7 @@ static void scan_submodules( fs::path const & path )
     {
         fs::directory_entry const & e = *it;
 
-        if( e.status().type() != fs::directory_file )
+        if( !fs::is_directory( it->status() ) )
         {
             continue;
         }
@@ -211,7 +218,7 @@ static void scan_module_path( fs::path const & dir, bool remove_prefix, std::map
 
         for( ; it != last; ++it )
         {
-            if( it->status().type() == fs::directory_file )
+            if( fs::is_directory( it->status() ) )
             {
                 continue;
             }
@@ -223,7 +230,11 @@ static void scan_module_path( fs::path const & dir, bool remove_prefix, std::map
                 header = header.substr( n+1 );
             }
 
+#ifdef BOOSTDEP_USE_STD_FS
+            std::ifstream is( it->path() );
+#else
             fs::ifstream is( it->path() );
+#endif
 
             scan_header_dependencies( header, is, deps, from );
         }
@@ -1669,7 +1680,7 @@ static void add_module_headers( fs::path const & dir, std::set<std::string> & he
 
         for( ; it != last; ++it )
         {
-            if( it->status().type() == fs::directory_file )
+            if( fs::is_directory( it->status() ) )
             {
                 continue;
             }