iostream overloads taking an SGPath

simgear/misc/sgstream.cxx

@@ -193,3 +193,17 @@ sg_gzofstream::attach( int fd, ios_openmode io_mode )
 {
     gzbuf.attach( fd, io_mode );
 }
+
+
+sg_ifstream::sg_ifstream(const SGPath& path, ios_openmode io_mode)
+{
+    std::string ps = path.local8BitStr();
+    open(ps.c_str(), io_mode);
+}
+
+
+sg_ofstream::sg_ofstream(const SGPath& path, ios_openmode io_mode)
+{
+    std::string ps = path.local8BitStr();
+    open(ps.c_str(), io_mode);
+}

simgear/misc/sgstream.hxx

@@ -35,6 +35,7 @@
 
 #include <istream>
 #include <ostream>
+#include <fstream>
 
 #include <string>
 
@@ -171,5 +172,17 @@ private:
     void operator= ( const sg_gzofstream& );
 };
 
+class sg_ifstream : public std::ifstream
+{
+public:
+    sg_ifstream(const SGPath& path, ios_openmode io_mode = ios_in | ios_binary);
+};
+
+class sg_ofstream : public std::ofstream
+{
+public:
+    sg_ofstream(const SGPath& path, ios_openmode io_mode = ios_out | ios_binary);
+};
+
 #endif /* _SGSTREAM_HXX */