use 64bit file offsets and _ftelli64/_fseeki64 on Windows + specialize some FileStream methods

octa/io.hh

@@ -8,6 +8,7 @@
 
 #include <stdio.h>
 
+#include "octa/platform.hh"
 #include "octa/string.hh"
 #include "octa/stream.hh"
 #include "octa/format.hh"
@@ -86,11 +87,19 @@ struct FileStream: Stream {
     }
 
     bool seek(StreamOffset pos, StreamSeek whence = StreamSeek::set) {
+#ifndef OCTA_PLATFORM_WIN32
         return fseeko(p_f, pos, int(whence)) >= 0;
+#else
+        return _fseeki64(p_f, pos, int(whence)) >= 0;
+#endif
     }
 
     StreamOffset tell() const {
+#ifndef OCTA_PLATFORM_WIN32
         return ftello(p_f);
+#else
+        return _ftelli64(p_f);
+#endif
     }
 
     bool flush() { return !fflush(p_f); }
@@ -103,6 +112,18 @@ struct FileStream: Stream {
         return fwrite(buf, 1, count, p_f);
     }
 
+    int getchar() {
+        return fgetc(p_f);
+    }
+
+    bool putchar(int c) {
+        return  fputc(c, p_f) != EOF;
+    }
+
+    bool write(const char *s) {
+        return fputs(s, p_f) != EOF;
+    }
+
     void swap(FileStream &s) {
         octa::swap(p_f, s.p_f);
         octa::swap(p_owned, s.p_owned);

octa/stream.hh

@@ -8,6 +8,7 @@
 
 #include <sys/types.h>
 
+#include "octa/platform.hh"
 #include "octa/types.hh"
 #include "octa/range.hh"
 #include "octa/type_traits.hh"
@@ -17,8 +18,11 @@
 
 namespace octa {
 
-/* off_t is POSIX - will also work on windows with mingw/clang, but FIXME */
+#ifndef OCTA_PLATFORM_WIN32
 using StreamOffset = off_t;
+#else
+using StreamOffset = __int64;
+#endif
 
 enum class StreamSeek {
     cur = SEEK_CUR,