From efcea3a80da7c4479d5fe168435ecc9fd06bdc72 Mon Sep 17 00:00:00 2001
From: John Turner <jturner.usa@gmail.com>
Date: Sun, 14 Sep 2025 00:16:10 -0400
Subject: Squashed 'subprojects/boost-sqlite/' content from commit 3378e35

git-subtree-dir: subprojects/boost-sqlite
git-subtree-split: 3378e353705271e569cf4ba15c467b840a39798c
---
 include/boost/sqlite/collation.hpp | 140 +++++++++++++++++++++++++++++++++++++
 1 file changed, 140 insertions(+)
 create mode 100644 include/boost/sqlite/collation.hpp

(limited to 'include/boost/sqlite/collation.hpp')

diff --git a/include/boost/sqlite/collation.hpp b/include/boost/sqlite/collation.hpp
new file mode 100644
index 0000000..a4624c4
--- /dev/null
+++ b/include/boost/sqlite/collation.hpp
@@ -0,0 +1,140 @@
+//
+// Copyright (c) 2022 Klemens Morgenstern (klemens.morgenstern@gmx.net)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_SQLITE_COLLATION_HPP
+#define BOOST_SQLITE_COLLATION_HPP
+
+#include <boost/sqlite/connection.hpp>
+#include <boost/sqlite/detail/exception.hpp>
+
+BOOST_SQLITE_BEGIN_NAMESPACE
+
+///@{
+/** Define a custom collation function
+ @ingroup reference
+
+ @param conn A connection to the database in which to install the collation.
+ @param name The name of the collation.
+ @param func The function
+
+ The function must be callable with two `string_view` and return an int, indicating the comparison results.
+
+ @par Example
+
+ @code{.cpp}
+
+ // a case insensitive string omparison, e.g. from boost.urls
+ int ci_compare(string_view s0, string_view s1) noexcept;
+
+ extern sqlite::connection conn;
+
+ // Register the collation
+ sqlite::create_collation(conn, "iequal", &ci_compare);
+
+ // use the collation to get by name, case insensitively
+ conn.query("select first_name, last_name from people where first_name = 'Klemens' collate iequal;");
+
+ // order by names case insensitively
+ conn.query("select * from people order by last_name collate iequal asc;");
+
+ @endcode
+
+ */
+
+template<typename Func>
+void create_collation(
+    connection & conn,
+    cstring_ref name,
+    Func && func,
+    typename std::enable_if<
+        std::is_convertible<
+            decltype(func(string_view(), string_view())),
+            int>::value,
+        system::error_code>::type & ec)
+{
+    using func_type = typename std::decay<Func>::type;
+    unique_ptr<func_type> f{new (memory_tag{}) func_type(std::forward<Func>(func))};
+    if (f == nullptr)
+    {
+      BOOST_SQLITE_ASSIGN_EC(ec, SQLITE_NOMEM);
+      return;
+    }
+    auto res = sqlite3_create_collation_v2(
+        conn.handle(),
+        name.c_str(),
+        SQLITE_UTF8,
+        f.get(),
+        +[](void * data, int len_l, const void * str_l, int len_r, const void * str_r) -> int
+        {
+          string_view l(static_cast<const char*>(str_l), len_l);
+          string_view r(static_cast<const char*>(str_r), len_r);
+          auto & impl = (*static_cast<func_type*>(data));
+          static_assert(noexcept(impl(l, r)),
+                        "Collation function must be noexcept");
+          return impl(l, r);
+        },
+        +[](void * p) { delete_(static_cast<func_type*>(p)); }
+      );
+    
+    if (res != SQLITE_OK)
+      BOOST_SQLITE_ASSIGN_EC(ec, res);
+    else
+      f.release();
+}
+
+
+template<typename Func>
+auto create_collation(
+    connection & conn,
+    cstring_ref name,
+    Func && func)
+#if !defined(BOOST_SQLITE_GENERATING_DOCS)
+    -> typename std::enable_if<
+          std::is_convertible<
+              decltype(func(string_view(), string_view())),
+              int>::value>::type
+#endif
+{
+    system::error_code ec;
+    create_collation(conn, name, std::forward<Func>(func), ec);
+    if (ec)
+        detail::throw_error_code(ec, BOOST_CURRENT_LOCATION);
+}
+
+
+inline void delete_collation(
+    connection & conn,
+    cstring_ref name,
+    system::error_code & ec)
+{
+    auto res = sqlite3_create_collation_v2(
+        conn.handle(),
+        name.c_str(),
+        SQLITE_UTF8,
+        nullptr, nullptr, nullptr);
+    if (res != SQLITE_OK)
+    {
+        BOOST_SQLITE_ASSIGN_EC(ec, res);
+    }
+}
+
+
+inline auto delete_collation(
+    connection & conn,
+    cstring_ref name)
+{
+    system::error_code ec;
+    delete_collation(conn, name, ec);
+    if (ec)
+        detail::throw_error_code(ec, BOOST_CURRENT_LOCATION);
+}
+
+/// @}
+
+BOOST_SQLITE_END_NAMESPACE
+
+#endif //BOOST_SQLITE_COLLATION_HPP
-- 
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