Added UTF-8 locale test to u8arguments, some cleanup.

CMakeLists.txt

@@ -1,7 +1,9 @@
-cmake_minimum_required(VERSION 3.2)
+cmake_minimum_required(VERSION 3.10)
 project(ghcfilesystem)
 
 set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
 add_compile_options("$<$<C_COMPILER_ID:MSVC>:/utf-8>")
 add_compile_options("$<$<CXX_COMPILER_ID:MSVC>:/utf-8>")

README.md

@@ -152,7 +152,7 @@ argument as the `fstream` variants in C++17 have them.
 
 ### `ghc::filesystem::u8arguments`
 
-This is a helper class that acts neutral on non-Windows platforms but on Windows it
+This is a helper class that currently checks for UTF-8 encoding on non-Windows platforms but on Windows it
 fetches the command line arguments als Unicode strings from the OS with
 
 ```cpp
@@ -170,6 +170,10 @@ namespace fs = ghc::filesystem;
 int main(int argc, char* argv[])
 {
     fs::u8arguments u8guard(argc, argv);
+    if(u8guard.valid()) {
+        std::cerr << "Bad encoding, needs UTF-8." << std::endl;
+        exit(EXIT_FAILURE);
+    }
 
     // now use argc/argv as usual, they have utf-8 enconding on windows
     // ...

examples/CMakeLists.txt

@@ -1,17 +1,21 @@
 
 add_executable(fs_dir dir.cpp ../filesystem.h)
-target_compile_definitions(fs_dir PRIVATE _CRT_SECURE_NO_WARNINGS)
+if(CMAKE_CXX_COMPILER_ID MATCHES MSVC)
+    target_compile_definitions(fs_dir PRIVATE _CRT_SECURE_NO_WARNINGS)
+endif()
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" AND (CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL 7.0 OR CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 7.0))
     add_executable(std_fs_dir dir.cpp)
     set_property(TARGET std_fs_dir PROPERTY CXX_STANDARD 17)
     target_link_libraries(std_fs_dir -lc++fs)
 endif()
+
 if (CMAKE_COMPILER_IS_GNUCXX AND (CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL 8.0 OR CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 8.0))
     add_executable(std_fs_dir dir.cpp)
     set_property(TARGET std_fs_dir PROPERTY CXX_STANDARD 17)
     target_link_libraries(std_fs_dir -lstdc++fs)
 endif()
+
 if(CMAKE_CXX_COMPILER_ID MATCHES MSVC AND (CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL 19.15 OR CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 19.15))
     add_executable(std_fs_dir dir.cpp)
     set_property(TARGET std_fs_dir PROPERTY CXX_STANDARD 17)

examples/dir.cpp

@@ -31,6 +31,10 @@ int main(int argc, char* argv[])
 {
 #ifdef GHC_FILESYSTEM_VERSION
     fs::u8arguments u8guard(argc, argv);
+    if(!u8guard.valid()) {
+        std::cerr << "Invalid character encoding, UTF-8 based encoding needed." << std::endl;
+        std::exit(EXIT_FAILURE);
+    }
 #endif
     if(argc > 2) {
         std::cerr << "USAGE: dir <path>" << std::endl;

filesystem.h

@@ -62,21 +62,22 @@
 #error "Operating system currently not supported!"
 #endif
 
-#ifndef GHC_OS_WINDOWS
+#ifdef GHC_OS_WINDOWS
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <wchar.h>
+#include <windows.h>
+#include <winioctl.h>
+#else
 #include <dirent.h>
 #include <fcntl.h>
+#include <langinfo.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <sys/statvfs.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
-#else
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <wchar.h>
-#include <windows.h>
-#include <winioctl.h>
 #endif
 #ifdef GHC_OS_MACOS
 #include <Availability.h>
@@ -917,11 +918,17 @@ public:
         _refargv = _argv;
     }
 
+    bool valid() const
+    {
+        return _isvalid;
+    }
+
 private:
     int _argc;
     char** _argv;
     int& _refargc;
     char**& _refargv;
+    bool _isvalid;
 #ifdef GHC_OS_WINDOWS
     std::vector<std::string> _args;
     std::vector<char*> _argp;
@@ -1203,25 +1210,6 @@ inline void postprocess_path_with_format(path::string_type& p, path::format fmt)
 
 }  // namespace detail
 
-inline u8arguments::u8arguments(int& argc, char**& argv)
-    : _argc(argc)
-    , _argv(argv)
-    , _refargc(argc)
-    , _refargv(argv)
-{
-#ifdef GHC_OS_WINDOWS
-    LPWSTR* p;
-    p = ::CommandLineToArgvW(::GetCommandLineW(), &argc);
-    _args.reserve(argc);
-    _argp.reserve(argc);
-    for (size_t i = 0; i < argc; ++i) {
-        _args.push_back(detail::toUtf8(std::wstring(p[i])));
-        _argp.push_back((char*)_args[i].data());
-    }
-    argv = _argp.data();
-    ::LocalFree(p);
-#endif
-}
 
 template <class Source, typename>
 inline path::path(const Source& source, format fmt)
@@ -1667,6 +1655,34 @@ inline file_status status_ex(const path& p, std::error_code& ec, file_status* sl
 
 }  // namespace detail
 
+
+inline u8arguments::u8arguments(int& argc, char**& argv)
+    : _argc(argc)
+    , _argv(argv)
+    , _refargc(argc)
+    , _refargv(argv)
+    , _isvalid(false)
+{
+#ifdef GHC_OS_WINDOWS
+    LPWSTR* p;
+    p = ::CommandLineToArgvW(::GetCommandLineW(), &argc);
+    _args.reserve(argc);
+    _argp.reserve(argc);
+    for (size_t i = 0; i < argc; ++i) {
+        _args.push_back(detail::toUtf8(std::wstring(p[i])));
+        _argp.push_back((char*)_args[i].data());
+    }
+    argv = _argp.data();
+    ::LocalFree(p);
+    _isvalid = true;
+#else
+    std::setlocale(LC_ALL, "");
+    if(!detail::compare_no_case(::nl_langinfo(CODESET), "UTF-8")) {
+        _isvalid = true;
+    }
+#endif
+}
+
 //-----------------------------------------------------------------------------
 // 30.10.8.4.1 constructors and destructor