Add `Out_channel.{is,set}_buffered` to control buffering of output channels (#10538)

1 files changed, 16 insertions, 0 deletions

diff --git a/stdlib/out_channel.mli b/stdlib/out_channel.mli
index 9b94eaaaba..8a70b50cda 100644
--- a/stdlib/out_channel.mli
+++ b/stdlib/out_channel.mli
@@ -129,3 +129,19 @@ val set_binary_mode : t -> bool -> unit
 
     This function has no effect under operating systems that do not distinguish
     between text mode and binary mode. *)
+
+val set_buffered : t -> bool -> unit
+(** [set_buffered oc true] sets the channel [oc] to {e buffered} mode. In this
+    mode, data output on [oc] will be buffered until either the internal buffer
+    is full or the function {!flush} or {!flush_all} is called, at which point
+    it will be sent to the output device.
+
+    [set_buffered oc false] sets the channel [oc] to {e unbuffered} mode. In
+    this mode, data output on [oc] will be sent to the output device
+    immediately.
+
+    All channels are open in {e buffered} mode by default. *)
+
+val is_buffered : t -> bool
+(** [is_buffered oc] returns whether the channel [oc] is buffered (see
+    {!set_buffered}). *)