Add portable abstraction for opening files from Unicode filepaths

src/SFML/System/FileInputStream.cpp

@@ -27,6 +27,7 @@
 ////////////////////////////////////////////////////////////
 #include <SFML/System/Exception.hpp>
 #include <SFML/System/FileInputStream.hpp>
+#include <SFML/System/Utils.hpp>
 #ifdef SFML_SYSTEM_ANDROID
 #include <SFML/System/Android/Activity.hpp>
 #include <SFML/System/Android/ResourceStream.hpp>
@@ -78,11 +79,7 @@ bool FileInputStream::open(const std::filesystem::path& filename)
         return m_androidFile->tell().has_value();
     }
 #endif
-#ifdef SFML_SYSTEM_WINDOWS
-    m_file.reset(_wfopen(filename.c_str(), L"rb"));
-#else
-    m_file.reset(std::fopen(filename.c_str(), "rb"));
-#endif
+    m_file.reset(openFile(filename, "rb"));
     return m_file != nullptr;
 }
 

src/SFML/System/Utils.cpp

@@ -51,4 +51,14 @@ std::string formatDebugPathInfo(const std::filesystem::path& path)
     return oss.str();
 }
 
+std::FILE* openFile(const std::filesystem::path& filename, std::string_view mode)
+{
+#ifdef SFML_SYSTEM_WINDOWS
+    const std::wstring wmode(mode.begin(), mode.end());
+    return _wfopen(filename.c_str(), wmode.data());
+#else
+    return std::fopen(filename.c_str(), mode.data());
+#endif
+}
+
 } // namespace sf

src/SFML/System/Utils.hpp

@@ -31,8 +31,10 @@
 
 #include <filesystem>
 #include <string>
+#include <string_view>
 
 #include <cstddef>
+#include <cstdio>
 
 
 namespace sf
@@ -51,4 +53,6 @@ template <typename IntegerType, typename... Bytes>
     std::size_t index   = 0;
     return ((integer |= static_cast<IntegerType>(static_cast<IntegerType>(byte) << 8 * index++)), ...);
 }
+
+[[nodiscard]] SFML_SYSTEM_API std::FILE* openFile(const std::filesystem::path& filename, std::string_view mode);
 } // namespace sf