From 8e783e9af31bfde1fe254ed4b01b3f1d9474fdc6 Mon Sep 17 00:00:00 2001
From: Jochen Topf <jochen@topf.org>
Date: Fri, 6 Jan 2023 09:21:48 +0100
Subject: [PATCH 1/2] Remove the overengineered util::integer_to_buffer

It is only used in a single place and easily replaced by
fmt::to_string().
---
 src/osmtypes.hpp       |  5 +++--
 src/tagtransform-c.cpp |  3 +--
 src/util.hpp           | 21 ---------------------
 tests/test-util.cpp    | 18 ------------------
 4 files changed, 4 insertions(+), 43 deletions(-)

diff --git a/src/osmtypes.hpp b/src/osmtypes.hpp
index e21ecf719..1448ef233 100644
--- a/src/osmtypes.hpp
+++ b/src/osmtypes.hpp
@@ -189,9 +189,10 @@ class taglist_t
     }
 
     /// Add tag to list without checking for duplicates
-    void add_tag(char const *key, char const *value)
+    template <typename T>
+    void add_tag(char const *key, T&& value)
     {
-        m_tags.emplace_back(key, value);
+        m_tags.emplace_back(key, std::move(value));
     }
 
     /// Add tag to list if there is no tag with that key yet
diff --git a/src/tagtransform-c.cpp b/src/tagtransform-c.cpp
index 9da0c4102..066bcf11d 100644
--- a/src/tagtransform-c.cpp
+++ b/src/tagtransform-c.cpp
@@ -84,8 +84,7 @@ static void add_z_order(taglist_t *tags, bool *roads)
         z_order -= 100;
     }
 
-    util::integer_to_buffer z{z_order};
-    tags->add_tag("z_order", z.c_str());
+    tags->add_tag("z_order", fmt::to_string(z_order));
 }
 
 c_tagtransform_t::c_tagtransform_t(options_t const *options, export_list exlist)
diff --git a/src/util.hpp b/src/util.hpp
index 6bad7183b..5b5219300 100644
--- a/src/util.hpp
+++ b/src/util.hpp
@@ -25,27 +25,6 @@
 
 namespace util {
 
-class integer_to_buffer
-{
-    // This is enough for 64 bit integers
-    static constexpr std::size_t buffer_size = 21;
-
-public:
-    template <typename T>
-    explicit integer_to_buffer(T value)
-    {
-        auto const result =
-            fmt::format_to_n(m_buffer.begin(), buffer_size - 1, "{}", value);
-        assert(result.size < buffer_size);
-        *result.out = '\0';
-    }
-
-    char const *c_str() const noexcept { return m_buffer.data(); }
-
-private:
-    std::array<char, buffer_size> m_buffer{};
-};
-
 class double_to_buffer
 {
     static constexpr std::size_t buffer_size = 32;
diff --git a/tests/test-util.cpp b/tests/test-util.cpp
index 966f6319d..0a154e214 100644
--- a/tests/test-util.cpp
+++ b/tests/test-util.cpp
@@ -16,24 +16,6 @@
 #include <string>
 #include <vector>
 
-TEST_CASE("integer_to_buffer 1", "[NoDB]")
-{
-    util::integer_to_buffer buffer{1};
-    REQUIRE(std::strcmp(buffer.c_str(), "1") == 0);
-}
-
-TEST_CASE("integer_to_buffer max", "[NoDB]")
-{
-    util::integer_to_buffer buffer{std::numeric_limits<osmid_t>::max()};
-    REQUIRE(std::strcmp(buffer.c_str(), "9223372036854775807") == 0);
-}
-
-TEST_CASE("integer_to_buffer min", "[NoDB]")
-{
-    util::integer_to_buffer buffer{std::numeric_limits<osmid_t>::min()};
-    REQUIRE(std::strcmp(buffer.c_str(), "-9223372036854775808") == 0);
-}
-
 TEST_CASE("double_to_buffer 0", "[NoDB]")
 {
     util::double_to_buffer buffer{0.0};

From 6ff0321386b983610313cf202d730a355c46d843 Mon Sep 17 00:00:00 2001
From: Jochen Topf <jochen@topf.org>
Date: Fri, 6 Jan 2023 10:29:42 +0100
Subject: [PATCH 2/2] Simplify db_copy_mgr_t::add_value()

The reason we had a different implementation for "double" values here is
that std::to_string() uses the current locale for writing out numbers.
For integers this doesn't matter, but for doubles this could be
something different than a decimal point. The fmt::to_string() function
on the other hand always uses the default locale, so it doesn't have
this problem. So we can use this for integers as well as for doubles.
---
 src/db-copy-mgr.hpp | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/src/db-copy-mgr.hpp b/src/db-copy-mgr.hpp
index b09018b6c..f7449c877 100644
--- a/src/db-copy-mgr.hpp
+++ b/src/db-copy-mgr.hpp
@@ -290,13 +290,7 @@ class db_copy_mgr_t
     template <typename T>
     void add_value(T value)
     {
-        m_current->buffer += std::to_string(value);
-    }
-
-    void add_value(double value)
-    {
-        util::double_to_buffer tmp{value};
-        m_current->buffer += tmp.c_str();
+        m_current->buffer += fmt::to_string(value);
     }
 
     void add_value(std::string const &s) { add_value(s.c_str()); }