streams: reorder/document functions

Author: sipa

src/streams.h

@@ -430,9 +430,18 @@ class AutoFile
     /** Implementation detail, only used internally. */
     std::size_t detail_fread(Span<std::byte> dst);
 
+    /** Wrapper around fseek(). Will throw if seeking is not possible. */
     void seek(int64_t offset, int origin);
+
+    /** Find position within the file. Will throw if unknown. */
     int64_t tell();
 
+    /** Wrapper around FileCommit(). */
+    bool Commit();
+
+    /** Wrapper around TruncateFile(). */
+    bool Truncate(unsigned size);
+
     //
     // Stream subset
     //
@@ -453,9 +462,6 @@ class AutoFile
         ::Unserialize(*this, obj);
         return *this;
     }
-
-    bool Commit();
-    bool Truncate(unsigned size);
 };
 
 /** Wrapper around an AutoFile& that implements a ring buffer to