From ba39bb27305e4eb788f3538061a604e558714472 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dr=2E=20Patrick=20Urbanke=20=28=E5=8A=89=E8=87=AA=E6=88=90?=
 =?UTF-8?q?=29?= <patrick@getml.com>
Date: Mon, 8 Dec 2025 00:13:11 +0100
Subject: [PATCH] Replace enable_if with concepts (#106)

---
 include/sqlgen/ForeignKey.hpp | 15 ++++++---------
 include/sqlgen/JSON.hpp       | 16 ++++++++--------
 include/sqlgen/PrimaryKey.hpp | 20 ++++++++------------
 include/sqlgen/Unique.hpp     | 15 ++++++---------
 4 files changed, 28 insertions(+), 38 deletions(-)

diff --git a/include/sqlgen/ForeignKey.hpp b/include/sqlgen/ForeignKey.hpp
index 1e038af..c2233c2 100644
--- a/include/sqlgen/ForeignKey.hpp
+++ b/include/sqlgen/ForeignKey.hpp
@@ -47,14 +47,12 @@ struct ForeignKey {
 
   ForeignKey(const ForeignKey& _other) = default;
 
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   ForeignKey(const U& _value) : value_(_value) {}
 
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   ForeignKey(U&& _value) noexcept : value_(std::forward<U>(_value)) {}
 
   ~ForeignKey() = default;
@@ -78,9 +76,8 @@ struct ForeignKey {
   }
 
   /// Assigns the underlying object.
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   auto& operator=(const U& _value) {
     value_ = _value;
     return *this;
diff --git a/include/sqlgen/JSON.hpp b/include/sqlgen/JSON.hpp
index d1c4f90..87bff46 100644
--- a/include/sqlgen/JSON.hpp
+++ b/include/sqlgen/JSON.hpp
@@ -27,16 +27,16 @@ class JSON {
   template <class U>
   JSON(JSON<U>&& _other) : value_(_other.get()) {}
 
-  template <class U, typename std::enable_if<std::is_convertible_v<U, T>,
-                                             bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, T>
   JSON(const U& _value) : value_(_value) {}
 
-  template <class U, typename std::enable_if<std::is_convertible_v<U, T>,
-                                             bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, T>
   JSON(U&& _value) noexcept : value_(std::forward<U>(_value)) {}
 
-  template <class U, typename std::enable_if<std::is_convertible_v<U, T>,
-                                             bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, T>
   JSON(const JSON<U>& _other) : value_(_other.value()) {}
 
   ~JSON() = default;
@@ -60,8 +60,8 @@ class JSON {
   }
 
   /// Assigns the underlying object.
-  template <class U, typename std::enable_if<std::is_convertible_v<U, T>,
-                                             bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, T>
   auto& operator=(const U& _value) {
     value_ = _value;
     return *this;
diff --git a/include/sqlgen/PrimaryKey.hpp b/include/sqlgen/PrimaryKey.hpp
index b5b5831..875a136 100644
--- a/include/sqlgen/PrimaryKey.hpp
+++ b/include/sqlgen/PrimaryKey.hpp
@@ -36,19 +36,16 @@ struct PrimaryKey {
   template <class U, bool _other_auto_incr>
   PrimaryKey(PrimaryKey<U, _other_auto_incr>&& _other) : value_(_other.get()) {}
 
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   PrimaryKey(const U& _value) : value_(_value) {}
 
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   PrimaryKey(U&& _value) noexcept : value_(std::forward<U>(_value)) {}
 
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   PrimaryKey(const PrimaryKey<U>& _other) : value_(_other.value()) {}
 
   ~PrimaryKey() = default;
@@ -72,9 +69,8 @@ struct PrimaryKey {
   }
 
   /// Assigns the underlying object.
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   auto& operator=(const U& _value) {
     value_ = _value;
     return *this;
diff --git a/include/sqlgen/Unique.hpp b/include/sqlgen/Unique.hpp
index 1a1b205..96b4792 100644
--- a/include/sqlgen/Unique.hpp
+++ b/include/sqlgen/Unique.hpp
@@ -25,14 +25,12 @@ struct Unique {
 
   Unique(const Unique& _other) = default;
 
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   Unique(const U& _value) : value_(_value) {}
 
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   Unique(U&& _value) noexcept : value_(std::forward<U>(_value)) {}
 
   ~Unique() = default;
@@ -56,9 +54,8 @@ struct Unique {
   }
 
   /// Assigns the underlying object.
-  template <class U,
-            typename std::enable_if<std::is_convertible_v<U, ReflectionType>,
-                                    bool>::type = true>
+  template <class U>
+    requires std::is_convertible_v<U, ReflectionType>
   auto& operator=(const U& _value) {
     value_ = _value;
     return *this;