From ef2beaea34cca0c4e31b9f9a8463e36ca2938d02 Mon Sep 17 00:00:00 2001
From: yhirose <yuji.hirose.bug@gmail.com>
Date: Sat, 18 Jul 2026 20:08:33 -0400
Subject: [PATCH] Fix MSVC C4146 warning for unsigned types in from_chars

The from_chars template is instantiated with unsigned types (e.g.
uint64_t for Content-Length), where unary minus on `result` triggers
MSVC warning C4146, failing the 32-bit build under warnings-as-errors.
Use `T(0) - result`, which yields the identical two's-complement value
without the warning.
---
 httplib.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/httplib.h b/httplib.h
index e2e6428..261790b 100644
--- a/httplib.h
+++ b/httplib.h
@@ -696,7 +696,7 @@ inline from_chars_result<T> from_chars(const char *first, const char *last,
     return {first, std::errc::invalid_argument};
   }
 
-  value = negative ? -result : result;
+  value = negative ? T(0) - result : result;
   return {p, std::errc{}};
 }