From 017e68b82f401fa3034f510a355fc15ff7bdc738 Mon Sep 17 00:00:00 2001
From: Marc Tiehuis <marc@tiehu.is>
Date: Sun, 24 Mar 2024 12:53:08 +1300
Subject: [PATCH] fix comptime float formatting

Closes #19379
Closes #18046
---
 lib/std/fmt.zig              | 2 ++
 lib/std/fmt/format_float.zig | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/std/fmt.zig b/lib/std/fmt.zig
index 511314fb12cf..df8397fb9330 100644
--- a/lib/std/fmt.zig
+++ b/lib/std/fmt.zig
@@ -1839,6 +1839,8 @@ test comptimePrint {
     try std.testing.expectEqualSlices(u8, "100", comptimePrint("{}", .{100}));
     try std.testing.expectEqualStrings("30", comptimePrint("{d}", .{30.0}));
     try std.testing.expectEqualStrings("30.0", comptimePrint("{d:3.1}", .{30.0}));
+    try std.testing.expectEqualStrings("0.05", comptimePrint("{d}", .{0.05}));
+    try std.testing.expectEqualStrings("5e-2", comptimePrint("{e}", .{0.05}));
 }
 
 test "parse u64 digit too big" {
diff --git a/lib/std/fmt/format_float.zig b/lib/std/fmt/format_float.zig
index b2194099bba4..13a3f3aad411 100644
--- a/lib/std/fmt/format_float.zig
+++ b/lib/std/fmt/format_float.zig
@@ -270,9 +270,9 @@ pub fn formatDecimal(buf: []u8, f_: FloatDecimal128, precision: ?usize) FormatEr
 
     // fixed bound: leading_digit(1) + point(1)
     const req_bytes = if (f.exponent >= 0)
-        2 + @abs(f.exponent) + olength + (precision orelse 0)
+        @as(usize, 2) + @abs(f.exponent) + olength + (precision orelse 0)
     else
-        2 + @max(@abs(f.exponent) + olength, precision orelse 0);
+        @as(usize, 2) + @max(@abs(f.exponent) + olength, precision orelse 0);
     if (buf.len < req_bytes) {
         return error.BufferTooSmall;
     }