From d943ce5dc79d2438ac82bb8e32baa33d3105306d Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Wed, 21 Feb 2024 00:14:48 -0700
Subject: [PATCH] std.io.Reader: add discard function

Reads the stream until the end, ignoring all the data.
Returns the number of bytes discarded.
---
 lib/std/io/Reader.zig | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/lib/std/io/Reader.zig b/lib/std/io/Reader.zig
index 0d96629e7a..9569d8d565 100644
--- a/lib/std/io/Reader.zig
+++ b/lib/std/io/Reader.zig
@@ -360,6 +360,18 @@ pub fn readEnum(self: Self, comptime Enum: type, endian: std.builtin.Endian) any
     return E.InvalidValue;
 }
 
+/// Reads the stream until the end, ignoring all the data.
+/// Returns the number of bytes discarded.
+pub fn discard(self: Self) anyerror!u64 {
+    var trash: [4096]u8 = undefined;
+    var index: u64 = 0;
+    while (true) {
+        const n = try self.read(&trash);
+        if (n == 0) return index;
+        index += n;
+    }
+}
+
 const std = @import("../std.zig");
 const Self = @This();
 const math = std.math;