Large reorganization of headers (WIP)

src/header/stdio/internal.rs

@@ -0,0 +1,31 @@
+use super::{constants, FILE};
+use platform::types::*;
+
+pub fn ftello(stream: &mut FILE) -> off_t {
+    let pos = stream.seek(
+        0,
+        if let Some((wbase, wpos, _)) = stream.write {
+            if (stream.flags & constants::F_APP > 0) && wpos > wbase {
+                constants::SEEK_END
+            } else {
+                constants::SEEK_CUR
+            }
+        } else {
+            constants::SEEK_CUR
+        },
+    );
+    if pos < 0 {
+        return pos;
+    }
+    let rdiff = if let Some((rpos, rend)) = stream.read {
+        rend - rpos
+    } else {
+        0
+    };
+    let wdiff = if let Some((wbase, wpos, _)) = stream.write {
+        wpos - wbase
+    } else {
+        0
+    };
+    pos - rdiff as i64 + wdiff as i64
+}