util/Concepts: remove obsolete fallbacks

src/util/Concepts.hxx

@@ -5,33 +5,5 @@
 
 #include <concepts>
 
-/**
- * Compatibility wrapper for std::invocable which is unavailable in
- * the Android NDK r25b and Apple Xcode.
- */
-#if !defined(ANDROID) && !defined(__APPLE__)
-template<typename F, typename... Args>
-concept Invocable = std::invocable<F, Args...>;
-#else
-template<typename F, typename... Args>
-concept Invocable = requires(F f, Args... args) {
-	{ f(args...) };
-};
-#endif
-
-/**
- * Compatibility wrapper for std::predicate which is unavailable in
- * the Android NDK r25b and Apple Xcode.
- */
-#if !defined(ANDROID) && !defined(__APPLE__)
-template<typename F, typename... Args>
-concept Predicate = std::predicate<F, Args...>;
-#else
-template<typename F, typename... Args>
-concept Predicate = requires(F f, Args... args) {
-	{ f(args...) } -> std::same_as<bool>;
-};
-#endif
-
 template<typename F, typename T>
-concept Disposer = Invocable<F, T *>;
+concept Disposer = std::invocable<F, T *>;

src/util/IntrusiveHashSet.hxx

@@ -182,7 +182,7 @@ public:
 		counter.reset();
 	}
 
-	void remove_and_dispose_if(Predicate<const_reference> auto pred,
+	void remove_and_dispose_if(std::predicate<const_reference> auto pred,
 				   Disposer<value_type> auto disposer) noexcept {
 		for (auto &bucket : table)
 			counter -= bucket.remove_and_dispose_if(pred, disposer);
@@ -200,7 +200,7 @@ public:
 	}
 
 	constexpr void remove_and_dispose_if(const auto &key,
-					     Predicate<const_reference> auto pred,
+					     std::predicate<const_reference> auto pred,
 					     Disposer<value_type> auto disposer) noexcept {
 		auto &bucket = GetBucket(key);
 		counter -= bucket.remove_and_dispose_if([this, &key, &pred](const auto &item){
@@ -296,7 +296,7 @@ public:
 	 */
 	[[nodiscard]] [[gnu::pure]]
 	constexpr bucket_iterator find_if(const auto &key,
-					  Predicate<const_reference> auto pred) noexcept {
+					  std::predicate<const_reference> auto pred) noexcept {
 		auto &bucket = GetBucket(key);
 		for (auto &i : bucket)
 			if (equal(key, i) && pred(i))
@@ -320,9 +320,9 @@ public:
 	 */
 	[[nodiscard]] [[gnu::pure]]
 	constexpr bucket_iterator expire_find_if(const auto &key,
-						 Predicate<const_reference> auto expired_pred,
+						 std::predicate<const_reference> auto expired_pred,
 						 Disposer<value_type> auto disposer,
-						 Predicate<const_reference> auto match_pred) noexcept {
+						 std::predicate<const_reference> auto match_pred) noexcept {
 		auto &bucket = GetBucket(key);
 
 		for (auto i = bucket.begin(), e = bucket.end(); i != e;) {

src/util/IntrusiveList.hxx

@@ -271,7 +271,7 @@ public:
 	/**
 	 * @return the number of removed items
 	 */
-	std::size_t remove_and_dispose_if(Predicate<const_reference> auto pred,
+	std::size_t remove_and_dispose_if(std::predicate<const_reference> auto pred,
 					  Disposer<value_type> auto dispose) noexcept {
 		std::size_t result = 0;
 

src/util/SortList.hxx

@@ -3,10 +3,10 @@
 
 #pragma once
 
-#include "Concepts.hxx"
 #include "StaticVector.hxx"
 
 #include <algorithm> // for std::find_if()
+#include <concepts>
 
 /**
  * Move all items from #src to #dest, keeping both sorted.
@@ -17,7 +17,7 @@
 template<typename List>
 constexpr void
 MergeList(List &dest, List &src,
-	  Predicate<typename List::const_reference, typename List::const_reference> auto p) noexcept
+	  std::predicate<typename List::const_reference, typename List::const_reference> auto p) noexcept
 {
 	const auto dest_end = dest.end(), src_end = src.end();
 
@@ -59,7 +59,7 @@ MergeList(List &dest, List &src,
 template<typename List>
 constexpr void
 SortList(List &list,
-	 Predicate <typename List::const_reference, typename List::const_reference> auto p) noexcept
+	 std::predicate <typename List::const_reference, typename List::const_reference> auto p) noexcept
 {
 	using std::swap;