From dddcecb0340f58fca9d45703a8d1efb6f0e946cc Mon Sep 17 00:00:00 2001
From: ToruNiina <niina.toru.68u@gmail.com>
Date: Tue, 12 Mar 2019 23:37:46 +0900
Subject: [PATCH] fix: use snprintf instead of stringstream

to avoid the effect of locale
---
 toml/serializer.hpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/toml/serializer.hpp b/toml/serializer.hpp
index cb150bb..c4fb689 100644
--- a/toml/serializer.hpp
+++ b/toml/serializer.hpp
@@ -5,6 +5,7 @@
 #include "value.hpp"
 #include "lexer.hpp"
 #include <limits>
+#include <cstdio>
 
 namespace toml
 {
@@ -30,13 +31,12 @@ struct serializer
     }
     std::string operator()(const toml::floating f) const
     {
-        std::string token = [=] {
-            // every float value needs decimal point (or exponent).
-            std::ostringstream oss;
-            oss << std::setprecision(float_prec_) << std::showpoint << f;
-            return oss.str();
-        }();
+        const auto fmt = "%.*g";
+        const auto bsz = std::snprintf(nullptr, 0, fmt, int(this->float_prec_), f);
+        std::vector<char> buf(bsz + 1, '\0'); // +1 for null character(\0)
+        std::snprintf(buf.data(), buf.size(), fmt, int(this->float_prec_), f);
 
+        std::string token(buf.begin(), buf.end());
         if(token.back() == '.') // 1. => 1.0
         {
             token += '0';